15 Best Merino Wool Base Layers For Women

Your base layer can make or break your adventure. If it’s not performing to your standards, you may feel uncomfortable, or even worse, you might freeze. So, instead of you taking a risk with the wrong apparel, we’ve put together a list of the best Merino wool base layers for women to help you find the perfect shirt!

And while there are several base layer materials – silk, nylon, bamboo, etc. – we focus on our favorite natural material: Merino wool! It’s lightweight, temperature regulating, and has a soft next-to-skin feel. It doesn’t stink, either! What more could you ask for in a base layer?

So, without further ado, let’s dive into the 15 best women’s Merino wool base layers for every situation!

Disclosure: Merino Wool Gear DOES NOT sponsor products to maintain our genuineness and authenticity. However, as an affiliate member, we may earn a small commission from qualifying purchases.

Quick Women’s Merino Wool Base Layer Buying Guide

Finding the right base layer to fit your various interests can be challenging. Many of the picks you’ll see today look almost identical, yet each has particular features that set them apart.

So, to help guide you with your decision, we’ve created a quick Merino wool base layer buying guide. It would help if you considered each factor while scrolling down the list.

If you want to learn more about the buying criteria, click on the boxes below.

Best Overall Merino Wool Base Layer For Women

Smartwool Classic All-Season Long-Sleeve Base Layer

87% Merino / 13% Nylon | 150 gsm (lightweight) | Slim fit | 9 colors | Price: $$$

Pros: Best all-around performance | Expert design & versatile style | Multiple colors

Cons: May experience initial itchiness | Must launder fabric with care

As I’ve previously mentioned, I’m a Smartwool fangirl through and through. Something about their apparel just fits well with me. I love how their clothing looks simple but has well-designed performance features. And when it comes to Merino wool base layers, the performance of the Smartwool Classic All-Season LS Crew reigns supreme.

As you’ll see throughout this list, many of these base layers look roughly the same. So it’s the details that make the difference. With this Smartwool base layer, you get several technical features. The raglan sleeves eliminate shoulder seams (which reduces backpack strap chafing), and the side seams wrap around the front for a more secure fit. Smartwool even uses a particular stitching technique to improve ease of movement.

In addition to its technical design, this base layer is our best overall because of its comfortable, durable material. It’s soft, comfy wool spun around a sturdy nylon core. So, you still get all the odor-proof properties with added strength. And while we think the fabric is silky smooth, some users have reported initial itchiness. While this rarely happens, it usually goes away after the first wash.

Finally, Smartwool has recently reclassified their fabric weights, so this “all-season” base layer is an ultralight 150 gsm. If you’re looking for something heavier for the colder months, you can check out their 250 gsm midweight layer instead.

Best 100% Merino Wool Base Layer For Women

Icebreaker Women’s Merino 200 Oasis LS Crewe

100% Merino wool | 200 gsm (light-to-midweight) | Slim fit | 7 colors | Price: $$$$

Pros: Top warmth-to-weight ratio | Versatile design | Drop tail hem

Cons: Fit discrepancies (sleeves) | Pilling may occur

100% Merino; 100% comfort. The Icebreaker Oasis 200 crew is a classic, comfy base layer that’s one of the most versatile on our list. The 200 gsm light-to-midweight fabric offers layered insulation in colder conditions. Yet, it’s light enough to be worn as a standalone piece if the weather gets warmer.

This blend of performance and versatility is why it’s Icebreaker’s top-selling women’s base layer.

And while the fabric is top-in-class, the technical features and design choices set the Oasis 200 apart from other base layers. For one, the underarm gussets improve mobility and prevent underarm chafing. Moreover, the offset shoulder seams prevent shoulder irritation from wearing a backpack. In fact, all the seams are flat-locked to reduce irritation. There is even a drop tail hem for added lower back coverage. Icebreaker expertly designed this base layer for ultimate comfort and performance.

Despite the enhanced design properties, a few concerns are still worth noting. Some users have reported that while the shirt’s body is snug, the sleeves may drape loose. Although, I wear a small (5’1″, 110 lbs.), and the sleeves fit acceptably on me. Also, as with most 100% Merino wool clothing, you may experience some pilling in the wash. This is natural as non-uniform wool fibers migrate out of the material, strengthening it in the long term.

If you’re gearing up for your next adventure, give the Oasis 200 Crew – or any of Icebreaker’s base layers – a try. You will be warm and comfortable while performing at your best. Because your clothing should never stop you from being your best self.

Best Value Women’s Merino Wool Base Layer

Meriwool Women’s Long Sleeve Thermal Shirt

100% Merino wool | 250 gsm (midweight) | Slim fit | 9 colors | Price: $$

Pros: Best price-to-quality ratio | Perfect for layering | Surprisingly breathable

Cons: Short torso length | Long-term durability concerns

As you may have noticed, women’s Merino wool base layers can be expensive. Although, inexpensive options are available if you just need a basic shirt with no technical features. Among these cheaper alternatives, the one with the best quality is the Meriwool Women’s Thermal Shirt.

Like many of Meriwool’s products, the comfort and style of this base layer rival that of its more expensive competitors. It performs just as well as every other base layer we’ve tested. The 100%, 17.5-micron Merino wool feels just as soft as others. Moreover, the midweight fabric is an excellent cold-season layer while remaining breathable in milder conditions.

Although, there are a few concerns to note. For one, we’ve noticed that the hem length (torso length) is shorter than most base layers. So, if you’re taller, consult the sizing charts to understand how it fits. Also, some users have reported long-term durability problems. This is typically the case with 100% Merino wool clothing. So, to improve your garment life, follow proper care instructions.

So, if you’re looking for a cozy, high-performing base layer at a reasonable price, Meriwool is your best bet. This thermal shirt embodies Meriwool’s values of comfort, performance, and affordability (a significant emphasis on the last).

Most Unique Merino Wool Base Layer For Women

Kari Traa Smekker Base Layer Top

100% Merino wool | 190 gsm (lightweight) | Tailored fit | 6 colors (seasonal) | Price: $$$$

Pros: Stylish jacquard knit pattern | Enhanced temp. regulation | Designed for women, by women

Cons: Sizing discrepancies | Material is thinner than expected

Many base layers on this list are technically advanced but may lack style. They typically come in solid colors (as with most Merino wool clothing), which is not bad. However, you may want some extra flare and fashion in your wardrobe. That’s where the Kari Traa Smekker Base Layer Top comes into play.

The jacquard knit pattern isn’t just for show, either. This unique fabric technique creates flattering lines for a snugger fit. The design, in combination with soft, 100% Merino wool and flatlock seams, makes this women’s base layer one of our favorites for winter fashion!

Although this pattern is associated with thicker knitwear, the Smekker is lightweight. The 190 gsm will keep you warm as a base layer, but you may need something heavier (like the midweight Kari Traa Silja Half Zip) if you’re looking for a standalone top. Also, since this is a snug, tailored fit, you may want to size up if you want a more flowing, relaxed fit.

As with all of Kari Traa’s collections, the Smekker Base Layer Top is designed for women by women. They make women’s sportswear with your comfort, style, and performance. So, check out what they have to offer!

Best Heavyweight Merino Wool Base Layer For Women

Minus33 Tanana Women’s Expedition Crew

100% Merino wool | 400 gsm (heavyweight) | Regular fit | Only in black | Price: $$$$

Pros: Best-in-class warmth | Super comfortable | Simple yet flattering design

Cons: Only suitable for cold/freezing conditions | Limited color options

Aptly named after an Alaskan river & town, where temperatures average negative numbers five months out of the year, the Tanana Crew is the warmest top on our list. This 400 gsm base layer is nearly double the fabric weight of others yet provides an exponential increase in warmth. It has been tested in the Arctic, Antarctica, and even at the top of Mount Everest!

It may sound like we are repeating ourselves, but we can’t rave enough about the warmth of this base layer. Minus33 says it should only be worn as a layering piece in freezing temperatures, even for low-impact activities. Although, we’ve noticed it works as a standalone shirt in milder conditions.

The simple design with princess seams will hug your curves nicely. Still, it’s not skin-tight, but that’s for a reason. With a standard fit, there is more room to breathe and help regulate moisture on your skin. This fit type is common among Minus33 clothing.

Finally, the only real issue with the Tanana Crew is that it only comes in black. Although, it’s not like the color matters when you’re off on a cold-weather excursion. So, grab this heavyweight base layer – or other expedition gear from Minus33 – to prep for all your winter adventures.

Best Ultralight Merino Wool Base Layer For Women

Patagonia Long-Sleeved Capilene® Cool Merino Shirt

65% Merino / 35% recycled polyester | ~140 gsm (ultralight) | Standard fit | 5 colors | Price: $$$

Pros: Top moisture control | Breezy, soft feel | Sustainably & ethically sourced

Cons: Slightly see-through | Must launder ultralight fabric with care

The advantage of Merino wool as a base layer fabric is its excellent warmth-to-weight ratio. Therefore, you don’t always need a heavy shirt to get the job done. Sometimes, you’ll only need a basic, lightweight base layer that helps regulate moisture. And among those options, our favorite is the Patagonia Capilene® Cool Merino Shirt.

This technical 140 gsm (ultralight) offers best-in-class moisture control! In addition to improved moisture wicking and breathability, Patagonia includes side vents, set-in sleeves, and a slight drop hem to improve performance. Although, since the material is thin, it may appear semi-transparent. So, it may work better as a layer instead of a standalone piece.

The thing we love the most about this Patagonia Merino wool base layer is its minimal environmental impact. By itself, Merino wool is sustainable. However, Patagonia takes it to the next level. Their wool is certified to the Responsible Wool Standard (RWS), which focuses on animal welfare and pastureland management. Moreover, they use 35% recycled polyester (Capilene®) for added strength. They even follow the bluesign® system to ensure their supply chain process meets the highest environmental & safety standards.

And it’s not just the environment that Patagonia cares about. They also treat their people well! For example, this garment is Fair Trade Certified™, ensuring their factory workers make a livable wage. As big proponents of Merino wool ethics, this is a huge plus.

In short, this Patagonia Merino wool base layer is comfortable, layerable, breathable, affordable, and, best of all, sustainable. Grab yours today!

Best Women’s 1/4-Zip Merino Wool Base Layer

Ridge Merino Aspect 1/4-Zip Merino Wool Base Layer

84% Merino / 16% Nylon | 180 gsm (lightweight) | Snug fit | 3 colors | Price: $$$

Pros: First-rate durability | Versatile style & design | Relatively affordable

Cons: Limited availability | Hard to layer underneath

There are more base layer designs than just your basic shirt. For example, the traditional 1/4-zip pullover works well as a base layer since you can adjust the zipper to improve ventilation and performance. Moreover, its has a classic style, so you can wear it on the trail, at the store, or at home! And the one with the best combination of performance and style is the Ridge Merino Aspect 1/4 Zip.

Like Ridge Merino’s best-selling Aspect shirt, this 1/4-zip is designed for the rigors of the outdoors. The 180 gsm lightweight material (although Ridge Merino classifies it as midweight) is toasty but not too toasty, making it perfect for mild conditions. The flatlocked seams and raglan sleeves reduce potential chafing, while the extended hem length adds coverage. Ridge Merino even reinforces their fabric with (m)Force Technology to improve durability and garment life.

While it was designed for the outdoors, this 1/4-zip base layer is flattering enough for social gatherings and everyday wear. Even the thumbholes are discreetly hidden, so it doesn’t look too outdoorsy. We also love the snug, athletic fit. Although, you may have difficulty wearing anything more than a Merino wool bra underneath as you don’t want the fabric bunching up.

The only issue we have with this 1/4-zip Merino wool base layer is the limited selection. Only three colors are available now, and many sizes are sold out. Yet, as we’ve seen from the Ridge Merino Aspect leggings, new colors and styles are released seasonally. Still, you may want to get one sooner rather than later!

Best 3/4 Merino Wool Base Layer For Women

Woolx Jenny 3/4-Sleeve Crew Neck

85% Merino / 12% Nylon / 3% Spandex | 150 gsm (ultralight) | Loose fit | 5 colors | Price: $$$

Pros: Flowing, relaxed style | Soft, 17.5-micron wool | Cute pattern selection

Cons: Sleeves slightly longer than 3/4-length | Scoop neck design not for everyone

Base layers are typically designed with a slim, snug fit as other layers are intended to be worn over them. However, you may not need an athletic-looking shirt for everyday wear. So, if you’re looking for a base layer with a more casual, relaxed fit, the Woolx Jenny 3/4-Sleeve Crew may be your best option.

I love the 3/4-sleeve design (although it’s more like 7/8) because it feels less restrictive than full sleeves. Moreover, the ultralight, 17.5-micron fabric and loose fit allow a full range of motion. And if that’s not enough, Woolx uses 3% Spandex to provide extra stretch.

Yet the best part of this 3/4 Merino wool base layer is its unique, casual style. It’s versatile enough to be worn almost anywhere, although it may not be the best option for cold-weather adventures. Also, while we love the scoop neck design, some users have reported that it does not lay flat enough. We haven’t experienced this issue, but it’s still worth noting.

Finally, we love the color and pattern options for the Jenny crew. Throughout Woolx’s base layer collection, they offer vibrant pastel colors in both solid and striped patterns (with some seasonal additions). It’s like you’re getting the comfort and performance of a technical base layer in a more casual, everyday shirt.

Best Merino Wool Turtleneck Base Layer For Women

Duckworth Women’s Powder High Neck

50% Merino / 30% Acrylic / 20% Polyester | 300 gsm (heavyweight) | Loose fit | 4 colors | Price: $$$$$

Pros: Fashion meets function | Enhanced warmth features | Merino wool sourced exclusively in the USA

Cons: Torso length may be long for some | Rather expensive

I’ve never been a fan of traditional turtlenecks. They always make me feel like I’m being strangled, and to be honest, most of them are plain ugly. However, my distaste is no more. With a loose neck and versatile style, the Duckworth Powder High Neck is no traditional turtleneck. It’s so much better.

The Powder High Neck’s design is a unique blend of fashion meets function, which can be challenging to find in the world of Merino. The fit is relaxed and loose for that cozy Merino wool feeling (for a tighter fit, size down). The foldable cowl neck is comfy but not too bulky, making it uber functional. Moreover, the hem rests lower (mid-hip) for better coverage. Yet some shorter users (like myself) think it’s about a smidge too long, but who’s measuring?

The fashion and function aren’t the only things that make the Powder High Neck unique; it’s also the Merino wool. While most companies source their Merino wool from Australia or New Zealand, Duckworth sources it from their ranch in Montana. They control each step of the farm-to-closet process to ensure high-quality wool. With the Powder High Neck, we can see this expertise with the soft yet durable material. 

According to Duckworth, this “perennial bestseller” works best for those with an active-casual lifestyle. And, we agree! It’s perfect for coffee shop runs, Netflix marathons, or those chilly January trips to the gym. And while it’s on the more expensive side, I’m telling you, it’s worth it! This classic Merino wool “turtleneck” base layer will be your go-to shirt when the months get colder.

Best Women’s Merino Wool Base Layer For Running

Tracksmith Brighton Base Layer

52% Wool / 28% Nylon / 20% Polyester | ~145 gsm (ultralight) | Athletic fit | 3 colors | $$$

Pros: Best-in-class breathability | Seamless construction prevents chafing | Silky 16.5 micron fibers

Cons: Pilling to be expected | No thumbholes

It can be challenging to find the best running outfit for chilly conditions. On the one hand, you don’t want to layer too much and overheat. On the other, you need adequate protection from the elements so you don’t freeze yourself to death. This is why Merino wool – in all its temperature-regulating glory – is the best material for high-performance running shirts. And the Tracksmith Brighton Base Layer is the best shirt for high-performance runners.

For example, the engineered Merino wool mesh is centered around the chest & midsection. This better ventilates your core, which generates the most body heat. In addition, Tracksmith partnered with expert sewists in Europe to create a seam-free interior! The seamless construction reduces any potential rubbing or chafing, so you can have a more seamless run.

In terms of the fabric, the wool-synthetic blend aids in durability, as pure Merino wool fibers at this size and weight (16.5-micron, 145 gsm) are delicate. Still, you may experience some pilling during the first few wash cycles. Remember, pilling isn’t necessarily bad, as the weak fibers migrate out of the material. Moreover, since wool doesn’t stink, laundry is less frequent, and there are fewer stinky running clothes everywhere.

Whether you’re a weekend warrior, devout morning jogger, or on-again-off-again athlete, the Brighton Base Layer should be your go-to Merino wool running shirt. Inspired by running legends and designed by running experts, you’ll no longer worry about what to wear. And who knows, maybe it will shave a few seconds off your mile time?

Best Women’s Base Layer For Hiking

Helly-Hansen LIFA® Merino Midweight Half-Zip Base Layer

57% Merino / 43% synthetic (100% wool ext.) | 225 gsm (midweight) | Athletic fit | 6 colors | Price: $$$$

Pros: 2-in-1 design for moisture management | Versatile cold-weather layer | Quality 1/2-zipper

Cons: Sizing discrepancies | Seams appear unnecessarily thick

You don’t want to freeze your butt off while you’re dozens of miles from civilization. Although you don’t want to carry too much weight in your backpack, you won’t be able to hike as far. So, if you’re headed out on the trail, one of the best Merino wool base layers options is the Helly-Hansen LIFA® Merino Midweight Half-Zip.

What sets this half-zip base layer apart is the unique 2-in-1 construction. Helly-Hansen uses their LIFA® Stay Warm technology for the inner layer, which offers best-in-class moisture-wicking. Meanwhile, the exterior is 100% Merino wool which aids in warmth and breathability. In addition, the half-zip allows for better ventilation if you start to get too hot. All these features work together to remove sweat from your skin, keeping you dry and warm while exploring the backcountry.

We love the athletic, tailored fit that sits snug and cozy against the body. However, some users note that the fit may be too tight. To be safe, consult Helly-Hansen’s sizing charts if you’re interested. Also, you may notice that the shoulder seams are relatively wide. This is because the thicker seams improve durability. So, it may not be the chicest design, but it will serve you when you’re using the same base layer five years later.

Finally, while we’ve classified the LIFA® Merino Half-Zip as the best hiking base layer, we really mean cold-weather hiking. Helly-Hansen offers a lightweight version of the same design if you’re hiking in milder temperatures. Otherwise, if you need a warm, versatile base layer for any winter sport, we think you’ll really enjoy this base layer.

Best Women’s Base Layer For Cycling

PEARL iZUMi Merino Thermal Long-Sleeve Base Layer

58% recycled polyester / 42% Merino | 250 gsm (midweight) | Slim fit | Charcoal only | Price: $$$

Pros: Easily layerable | Technical features for smoother riding | Recycled, sustainable fabric

Cons: Limited availability | Not 100% odor-resistant

In my little cycling experience, I’ve noticed that ultralight and lightweight base layers don’t provide enough protection during cold-weather rides. Moreover, throwing on a layer overtop makes me sweat like a pig. Although, if I wear a midweight base layer, I usually can last hours on my bike in any condition. And the best midweight cycling layer – Merino wool or not – is the PEARL iZUMi Merino Thermal Long-Sleeve.

The best part about this base layer – and all PEARL iZUMi apparel – is that it was designed purely for cyclists. The set-in sleeves and tagless interior help to control chafing on long rides, while the thumb loops keep your sleeves in place. What else would you expect from one of the best cycling apparel brands on the market?

And, as always, we have to talk about the Merino wool. This has a lower wool content than other products, but that’s a purposeful design choice. The recycled polyester does better at wicking sweat away from your skin as you pedal. However, this comes at the cost of being less odor-proof than fabrics with a higher wool percentage.

Still, we love the soft, 18.5-micron midweight fabric. Although, if you’re looking for something a little lighter to wear under your jersey, PEARL iZUMi offers a lightweight version of this Merino wool base layer. Since both shirts have limited availability, you should jump at the opportunity to get one before they’re gone!

Best Women’s Merino Wool Ski Base Layer

Mons Royale Monsie One-Piece Baselayer

100% Merino wool | 190 gsm (lightweight) | Standard fit | 2 colors | Price: $$$$$

Pros: Easy front, rear, & full-body access | 3/4 length designed for ski boots | Hood fits helmet

Cons: Not super versatile | Not as form-fitting as you would expect

I know what you’re thinking: “Really? A Merino wool onesie?” And yes, yes, it is. The Mons Royale Monsie is a unique, warm, and comfy base layer for ultimate winter performance. The 190 gsm lightweight fabric is just the right thickness to keep you warm under your ski jacket and snow pants without causing you to overheat. Moreover, the mesh back and front zipper vent away any excess moisture.

And we understand that the onesie is not the most versatile style. However, it was not designed to be! Mons Royale specifically created this piece for the slopes. The 3/4-length legs and reinforced thumb loops prevent fabric bunching. Also, the hood fits snugly under your helmet. So there’s no need for a bulky balaclava when you hit the slopes (although I usually bring a Merino wool buff just in case). 

The one concern many skiers have with onesies is their ease of access. If you really have to go, you probably don’t want to completely undress, especially if it’s freezing. Luckily, Mons Royale expertly crafted the onesie with an envelope fly and full-width rear zipper whenever nature calls.

Finally, you may be hesitant about purchasing an actual Merino wool onesie. We get it; we really do. But if you’re an adrenaline-fueled snow bunny, there is no better way to stay warm in the backcountry than using a onesie as a base layer. And, the best Merino wool onesie on the market – in our not-so-expert opinion – is the Mons Royale Monsie. Check it out for yourself!

Best Women’s Base Layer For Travel

Unbound Merino Long Sleeve Merino Crew

100% Merino wool | 150 gsm (ultralight) | Relaxe fit | 2 colors | Price: $$$

Pros: Easily dressed up or down | Luxuriously soft material | Packable & wrinkle-resistant

Cons: Sleeves may feel long or baggy | Limited availability

Within the last few years, Unbound Merino has made a name for themselves in men’s travel apparel. In the Spring of 2022, they launched their much-anticipated women’s collection filled with soft, comfy Merino wool gear. We’ve put their travel dress to the test, and it passed with flying colors. And in terms of travel base layers, their newly-launched long sleeve Merino crew is one of our favorites.

So why is this base layer such a must-have for travelers? Well, it’s simple. There are no tags or labels. You can easily dress it up with a nice pair of pants. Or, if you’re traveling in more tropical climates, it looks great with shorts, and the ultralight fabric weight will keep you cool no matter the temperature. Moreover, it’s wrinkle-resistant and doesn’t stink! Due to this unique versatility, you can pack less and travel more!

Another feature that sets this base layer apart is the flowing, classic fit. It’s relaxed but not too baggy that it can’t be worn as an underlayer. However, some users have reported that the looser sleeve construction does not fit all body types. I think the style adds to the design principle of simple versatility, but that’s just me.

Finally, since Unbound Merino’s women’s collection has been so popular since its release, they have been selling out fast. So, if you don’t see a color or size you like, you may want to pre-order a shirt instead! You shouldn’t have to wait long, though, as we reached out to them, and they assured us another wave of long-sleeve crews is in production.

Best Merino Wool Base Layer For Everyday Wear

Ibex 24-Hour LS Scoop Neck Crew

100% Merino wool | 150 gsm (ultralight) | Regular fit | 10 colors | Price: $$$

Pros: Fabric cooling technology | Vivid assortment of color options | Versatile construction

Cons: Neckline could be more “scooped” | Sizing & fit discrepancies

Many base layers you’ve read about today are designed for technical use. But let’s be honest; most people aren’t going to trek through the woods daily. And while Ibex typically creates apparel for these outdoor adventures, they also make everyday clothing like their 24-hour long-sleeve scoop neck.

What we love about this base layer is the minimalist yet elegant design. There is no flashiness or frills, just a basic, comfy base layer. The ultralight, 100% Merino wool fabric is finished with a unique steaming technique known as MECool, which makes it feel cooler. So, if you sweat randomly throughout the day, as I do, it will help regulate your body temperature.

Moreover, as with all of Ibex’s base layer collections, the 24-hour scoop neck comes in various colors. And it’s not just your basic earth tones either. There a vibrant shades like walnut, beetroot, evergreen, terracotta, soft moss, and French navy. In other words, there is bound to be a color that matches your daily style.

Although, as a big fan of a deep scoop neck, I have to say that the neckline is shallower than I would like. It seems to be more of a crew cut than a scoop, but I’m picky, so who knows? Still, it’s not a dealbreaker for us. And if it isn’t one for you, too, head to Ibex to check out this 24-hour base layer!

Final Note About Women’s Merino Wool Base Layers

There you have it! Our favorite 15 Merino wool base layers for women! We covered simple long-sleeve crews, quarter zips, and even a onesie. Hopefully, you found a layer that fits your lifestyle.

And, if you didn’t see a shirt that really won you over, don’t worry! There are dozens of other options out there. So, follow us on Instagram or any other major social channels. We’re bound to review a piece of Merino wool gear that is totally you!