Stay warm and comfortable with our women's long underwear collection, designed for ultimate performance in cold weather. Crafted from soft, moisture-wicking materials, these base layers provide excellent insulation while keeping you dry. The lightweight and breathable fabric ensures freedom of movement, making them perfect for outdoor adventures or lounging at home. With a variety of styles and fits, you can easily layer up without sacrificing comfort. Embrace the chill and enjoy your favorite activities with confidence in our high-quality long underwear.
$90.00
They ’ re comfortable, not scratchy, warm but breathable. ... Comfy, warm, and breathable ... Keeps me warm. ... [ This is super soft and comfortable. ... Great for outdoor
5
Wasloki
[ Bought for my wife for an upcoming trip to the Arctic. She loves them. She says they are soft and not itchy. Like they don ’ t require to much special treatment in the wash and don ’ t shrink
5
ErinH
[ These worked great for skiing in single digit to mid- 20 ’s temps. They ’ re comfortable, not scratchy, warm but breathable. Will definitely buy more.
4
runnergal832
Bought this a month ago for cold running weather. Wish it wasn ’ t see through but it does the job
4
Mnshopper1234
[ This is super soft and comfortable. I wear it under winter pants for long hikes, snow shoeing or cross country skiing. Keeps me warm.
$65.00-$130.00
WAS: $130.00*
It's their best thing in a very long time and I 've been a fan for years. ... The material is very soft, has a great but comfortable fit. ... They ’ re tight but flexible and
5
Hmae
[ Love the style. These are very warm and keep me toasty on those cold days. Would recommend to anyone looking for a quality under layers... very cute!
5
shellydk
[ I could go on and on about this whole line from Smartwool. It's their best thing in a very long time and I 've been a fan for years. The material is very soft, has a great but comfortable fit. These bottoms also have a nice wide and sturdy waste band so there is no bunching or other uncomfortable nonsense in that area. These are very warm, so perfect under a shell pant or bib for alpine skiing, but I do n't think I would wear them on a tour.
5
abeck
[ I received these as a Christmas gift. I love them under my bibs for snowboarding! They ’ re tight but flexible and comfortable. They keep me warm on the mountain.
4
Brenda
Fit is great. Very warm for Chicago winter runs, but a little bit itchy. Also I would like it to be thinner like the ones in the smartwool Tercel material. Sadly could not find those in mid rise online.
$115.00
This shirt is so soft and warm! ... She loves it- Warm and cozy and fits like a glove! ... Material is so soft. ... It provides enough warmth without being bulky. ... Warm and
5
Track Mom
Material is so soft. It is also thicker than most other brand wool base layer tops I have bought. Smartwool is a great brand.
5
Raka
Fits well, comfortable and a breathable but warm base layer.
5
Valentine56
This shirt is so soft and warm! As a senior citizen, I get cold easily. Wearing this shirt to sleep in keeps me comfortably cozy.
5
Jill
This is a great product. I purchased one for myself on- line for Christmas, based on the previous smart wool base layer bought in the store in October 2024. The only problem is that the shoplifting tag was still on the product when I opened it on Christmas Day 2025. How Annoying!!!!!! Now I have to return the product. How about some quality control? This was a very unsatisfying purchase.
5
LT70
I bought this shirt about a month ago because it was on clearance. I have already used it a few times while cross- country skiing and it is great. It provides enough warmth without being bulky. I am satisfied with my purchase.
$115.00
I got These for skiing and they were pretty warm and comfortable. ... It ’s a great base layer that I can depend on. ... They are warm for sure but I can ’ t wait
5
Maw maw Z
My legs will not be cold this winter. They are of good quality and very soft and warm.
5
Sydroo
Fits true to size. Keeps you warm! Relaxed fit and love the color. Makes snowboarding more enjoyable.
5
Mim1
Used these under sweats in below freezing temperatures in Quebec City sometimes needed snow pants too, other times just the two layers.
5
DreambornAnthology
Love Smartwool for days in the snow. It ’s a great base layer that I can depend on. It is super soft when you first buy it but does get scratchier with wash and wear, even with gentle cycles, mild detergent, and hang drying. I tend to wear a thin, cotton free layer underneath for better comfort and more layers. While it does offer some stretch, it is very true to size, so if you are teetering between sizes, size up. You ’ ll be more comfortable and won ’ t risk circulation compression, which will ultimately make you more cold.
5
Kpave
[ These fit so great! I ’ m plus sized and sometimes sizing can be wonky or vague but these are a dream. They are warm for sure but I can ’ t wait until The temperature dips to really put tgem to the test.
$130.00
My favorite underlayer by a long shot, I literally wore it every day of my last ski trip- 5 days in a row. ... The color is very pretty and overall was a very comfortable base
5
G Love
[ This top made me ski like an olympiad. Really, it's that good, so I 'm buying it in navy. My favorite underlayer by a long shot, I literally wore it every day of my last ski trip- 5 days in a row. Shhhh.
5
Jess13
[ I bought this about 3 weeks ago… to keep me warm on a climbing trip where we would encounter cooler weather! I have dressed it up, wore around the cabin and out for hikes. I highly recommend!
5
Laurie
[ I bought this several weeks ago and have worn it on several chilly( and hilly) NE dog walks. It provides a warm, yet breathable layer under my light down jacket. It fits very close to my body and adds very little bulk. I appreciate the generous sleeve length. I have yet to launder it as I wear it as a middle layer.
5
Bouldergirl
[ This is my favorite top for hiking. It is the perfect weight and is useful all year round! I wear it's a base layer in winter and a top layer in summer for cooler days. Best material ever!
5
MPOSH
[ These Smartwool shirts are some of my favorite. They are a more snug fit, but not too tight. The purple color is so pretty. Very happy with this purchase.
$90.00
Not only do I look good because they fit beautifully but are lightweight; so I ’ m not bulky 😊 whether worn alone( burnt orange is hot 🔥) or layered under my sweater I ’ m warm and toasty…looking
5
T Oot
Just came back from Banff Canada and wore this base layer everyday. I was warm and dry in sero degree weather!
5
Wild Child
[ I rage- bought another one of these after a medical tech ruined the neckline of the first one during a procedure. Every time I want to put on something warm and reliably comfy, I reach for this top. I intend to buy one per year until I 've replaced every other base layer top I own. Very good quality, good feel to the fabric. I 'm fairly tall( 5'10 '') and the sleeves are long enough, and the body is long enough. So that's another thing.
5
Upshpr
[ For reference, I purchased a Medium. I ’ m 5 ’ 4 ”, 128 pounds, pear shaped, so, smaller on top, curvier on bottom. I got the black which is opaque. I wear this baselayer weight for cross country skiing when it ’s above 30 degrees or so. Smartwool varies in size for me, these are not extremely fitted like some of the 1/4 zips so go with your normal size.
5
KC123
[ I love this shirt. I recently got another few to fill up my wardrobe after a move from AZ to OR. I have had the originals for almost 9 years and wear them all winter long. I have been hiking, backpacking, and traveling with them and they have withstood the test of time. They are comfortable alone or as under layer. I additionally regularly wear it as a mid layer with a smartwool tank below. I truly love these shirts. If it helps, I wear an XS and am 5 ’ 2 ’ ’ and 120- 130lbs depending on the year.
5
Silvercurls
[ Bought my Smartwool Women's Classic All- Season Merino LS Base Layer Tops just in time for the cold weather in the “ D ”. Best referral from a friend ever! Not only do I look good because they fit beautifully but are lightweight; so I ’ m not bulky 😊 whether worn alone( burnt orange is hot 🔥) or layered under my sweater I ’ m warm and toasty…looking good! Not sweaty in this wool top; comfort is sexy, ok! Grabbing more for stocking stuffers 😊
See Price in Cart
WAS: $115.00*
Very warm and super comfortable for our Michigan winters. ... They always keep me warm and hold up wash after wash. ... It works great under clothes- let ’s your skin breathe and doesn ’ t absorb
5
gilllll
[ I bought this for a trip to Yellowstone national park. The color is a bit different from the photo in natural light. Less coral/orangish as I expected. A bit darker and a bit more pinkish. But it's still really pretty and of course warm and cozy as the other Smartwool 250 I owned.
5
Annie
[ I am addicted to smartwool 250 baselayers. They always keep me warm and hold up wash after wash. The material doesn ’ t pill at all. I wear them all fall and winter.
5
Connie
[ I purchased this and the smart wool 250 bottoms for camping/hiking. They are exactly what you think they are and do exactly what you want them to. Warm, lightweight, doesn ’ t stink, comfortable to sleep in and definitely a base layer option for hikes should you want one. I purchased the set on the mystery gift promo- 100% worth it. Value value value.
5
Ellen F
[ Best cozy layer ever. Bought crew and leggings. My walks in the cold weather are so much happier now! Easy to order and fast delivery. Recommend to anyone!!
5
limabean
[ Gave to my daughter for Christmas. She loves it! Large fit perfectly It is great fabric and perfect weight! Would purchase again! Would like it come in Navy.
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