Best Thermal Underwear Bottoms for Women of 2026

"I absolutely love these lined leggings! They are soft and warm without being bulky, perfect for winter. I initially ordered a Large, but they were a bit baggy behind the knees, so I switched to a medium, which fit perfectly. If you're between sizes, go smaller."

"These leggings are incredibly comfortable and buttery smooth while providing the perfect amount of warmth. I found them to be a little long, but they fit just right for my usual size. I will definitely be ordering more!"

"I gave these leggings 4 stars because I ordered the 3 pocket style but received one with only 2 pockets and no drawstring. The quality is good, but they didn't keep me warm in the snow as expected. However, they fit nicely and the length was perfect, so overall I'm satisfied."

"As someone who is very sensitive to the cold, I appreciate how these leggings keep me warm without needing a space heater. The material is soft, thick, and stretches nicely, offering comfort without being too loose. The pockets are secure for my phone and other items, and I’m thrilled to have found a pair that I’ll wear year-round. Highly recommend, especially for the price!"

"I’m really impressed with the Baleaf Fleece-lined leggings—they are super soft, extremely comfortable, and the Small fits my 5’8” frame perfectly. I can wear them all day without needing to adjust, and they keep me warm even at 45 degrees. The pockets are handy for keys or cards while jogging, though I avoid heavier items."

"After testing these out on a frigid day, I can say they’re worth every penny—super warm, supportive, yet not restrictive. Despite being not as thick as cheaper alternatives, they block out wind and keep my legs warm. The fit is great for my petite build, and I’m so glad I made the purchase!"

"I really appreciate how soft and cozy these leggings feel—they remind me of a fine-knit merino sweater, but they're not itchy at all. The heavyweight version kept me comfortable in freezing mountain temperatures without overheating indoors. I love the sleek look, and they don't have that synthetic sheen. They're perfect for my medieval reenactment events too! The only thing I would change is to maybe try a smaller size next time for a snugger waist, and an option with pockets would be nice."

"These leggings were a lifesaver during a big snowstorm and winter beach walks in the Northeast. The heavier 320 weight keeps my legs warm, even in extreme cold and wind. They're better than my old Smartwool pair and cost half as much! I love how they wick moisture, retain heat, and control odor—all perfect for backpacking or long hikes. Plus, the free wool socks are a great bonus."

"I wore these merino wool bottoms as a base layer for hiking in 11° snowy, windy weather and was impressed by how warm, soft, and comfortable they were. The ankle cuffs are smooth and don't add bulk under socks, and the waistband sits just right. The quality for the price is fantastic, and I plan to buy more for all-weather hiking."

"These leggings are amazingly soft and cozy, and the thickness is just right—substantial enough to wear alone, but still thin and perfect as a base layer in cold weather. The stretch and fit are spot-on, making them both comfortable and practical."

"I wore these under tight jeans during a week of cold weather travel in Italy, and they were a lifesaver. The fabric is silky, lightweight, and kept me warm without any bulk. They fit under everything and were comfortable all day long."

"I appreciate how lightweight and breathable these are, yet they provide surprising warmth. The material is soft against my skin, and there's plenty of stretch—no discomfort or tightness. I especially like that they work well as sleepwear too."

"I recently bought these leggings for a trip to NYC, and I was amazed by how incredibly warm and soft they are on the inside. Even when it was freezing (13-15°F feels like), my legs stayed toasty without needing another layer. The side pockets easily fit my large phone and the waistband is comfortable, not restrictive. I highly recommend these if you spend a lot of time outdoors in the winter, and I’m already planning to get more colors."

"As someone who runs outdoors in cold weather, I’m thrilled with these leggings. I ran 6 miles with a windchill of 0°F and my legs never felt cold. The waistband stays up, and the zippered pocket is perfect for my keys—I don’t even notice them while running. The fit and sizing are spot on, and I love the look and performance. These are hands down the most comfortable running tights I’ve owned."

"For working from home and chilly weather, these leggings are a game changer. The fleece lining is light yet warm, making them cozy without being bulky. I love that there are deep phone pockets and extra zippered pockets for essentials like cards or keys. The fit is snug but not tight, and they don’t leave seam marks on my legs. I practically live in these during the winter!"

"I found these thermal leggings to be incredibly comfortable and soft, with a fit that works perfectly under jeans without adding any bulk. They keep my legs warm even in 15-degree weather, and I appreciate that they don't sag. I'm 5'3" and 140 pounds, and a medium fits just right. I liked them so much, I bought two more pairs."

"As someone who spends long hours outdoors in Duluth, Minnesota, I've found these leggings to be the most versatile base layer I own. They're thin, smooth on the outside, and fleecy inside, so they layer well under office slacks or hiking pants without bunching. They're not too warm, making them great for various conditions. For subzero temps, I layer them under merino or fleece. For the price, they're incredibly useful—just keep them away from fire."

"During my winter adventure in Iceland, these leggings made a perfect base layer, providing exceptional comfort, warmth, and breathability. The fit was spot-on, and they kept me warm outdoors while still being comfortable indoors. They exceeded my expectations as a winter base layer—highly recommended for anyone needing reliable winter wear."

"I was unsure at first because these felt so thin, but they ended up being surprisingly warm as a base layer during my trip in 40-degree weather. The fabric is incredibly soft and comfortable, not at all like scratchy hosiery, and packed really easily for travel. I'm so happy I kept them."

"I wear these under my sheer black pants for extra insulation without bulk. They're lightweight, breathable, and comfortable all day—even easy to hand wash and dry overnight. I've bought two pairs and would definitely recommend them."

"These long underwear are perfect for layering under jeans and regular pants, keeping me warm and cozy without adding bulk. The wide waistband is comfortable for all-day wear, and the fabric is thin but durable. I appreciate that they fit both straight and curvy shapes."

"I was surprised by how thick and warm these leggings are—they kept us cozy during a chilly Halloween night and reached all the way to our ankles. They're super comfortable and definitely not see-through. For the price, the comfort and warmth are truly impressive."

"These leggings have become my go-to base layer for outdoor work in windy conditions. I now own three pairs because they’re soft, fit well, and the extra high waist keeps my midsection warm. They’re fitted without feeling tight, offer good stretch, and have held up after multiple washes. The sizing is accurate and the quality is great for the cost."

"If you want real fleece lining, these aren’t it, but the soft lining is just right—not too thick, not too hot. I wore them in single-digit temps and stayed warm without overheating indoors. The fit is comfortable, great quality, and not see-through. I love these so much, I plan to buy more!"

"I rely on these to keep me warm under my clothes during the chilly months in my area. They're super soft and comfortable, which is exactly what I need."

"These are the perfect light layer for wearing under jeans. I tend to get cold even indoors in the winter, and these Cuddl Duds are incredibly comfortable and keep me cozy."

"While the pants feel really nice and soft, I did notice they're a bit loose around the thighs and legs. I'll see how they work under other pants, but they might slip down a little because of the fit."

"I absolutely love how soft and warm these leggings are! As someone who is always cold due to thyroid issues, these have become my go-to for winter. The fit is perfect—I'm 5'4" and 167 lbs and the large size worked great. I'm so happy I found leggings that are both comfortable and insulating."

"These leggings are super comfortable, and I really appreciate the roomy pockets for my phone. At 5 feet tall, I often struggle with length, but these fit me just right and the waistband stays put. I’ll definitely be buying more pairs!"

"I was looking for something to wear during cooler motorcycle rides and these leggings are exactly what I needed. The material is as soft as a chinchilla and keeps me warm without overheating. The only minor downside is the lack of a pocket, but overall, this was one of my best purchases in a long time."