loaded 591 results

Underwear

(591 products)

Products (591)

Sort: Best Match

SmartwoolClassic Thermal Merino Base Layer Bottoms - Women's
$56.83 - $120.00
730 reviews with an average rating of 4.5 out of 5 stars
Top Rated
SmartwoolClassic Thermal Merino Base Layer Bottoms - Men's
$115.00
613 reviews with an average rating of 4.7 out of 5 stars
Top Rated
REI Co-opMidweight Long-Sleeve Base Layer Top - Men's
$37.93 - $54.95
146 reviews with an average rating of 4.5 out of 5 stars
REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's
$39.83 - $79.95
191 reviews with an average rating of 4.5 out of 5 stars
REI Co-opMerino 185 Base Layer Bottoms - Men's
$55.93 - $79.95
119 reviews with an average rating of 4.4 out of 5 stars
Top Rated
REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men's
$79.95
163 reviews with an average rating of 4.5 out of 5 stars
REI Co-opMidweight Base Layer Bottoms - Men's
$54.95
77 reviews with an average rating of 4.4 out of 5 stars
SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's
$35.83 - $90.00
101 reviews with an average rating of 4.4 out of 5 stars
REI Co-opMidweight Long-Sleeve Base Layer Top - Women's
$37.93 - $54.95
234 reviews with an average rating of 4.3 out of 5 stars
REI Co-opMerino 185 Base Layer Bottoms - Women's
$55.93 - $79.95
102 reviews with an average rating of 4.3 out of 5 stars
REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women's
$39.95
0 reviews
SmartwoolClassic All-Season Merino Quarter-Zip Base Layer Top - Men's
$95.00
0 reviews
SmartwoolClassic All-Season Merino Base Layer Bottoms - Men's
$90.00
18 reviews with an average rating of 4.1 out of 5 stars
VuoriAll The Feels Bra
$58.00
3 reviews with an average rating of 5.0 out of 5 stars
REI Co-opMidweight Base Layer Tights - Women's
$15.83 - $54.95
89 reviews with an average rating of 4.1 out of 5 stars
BrooksConvertible 2.0 Sports Bra
$29.83 - $60.00
79 reviews with an average rating of 3.6 out of 5 stars
SmartwoolClassic All-Season Merino Quarter-Zip Base Layer Top - Women's
$95.00
1 reviews with an average rating of 5.0 out of 5 stars
Top Rated
SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Women's
$83.93 - $120.00
24 reviews with an average rating of 4.9 out of 5 stars
Top Rated
REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's
$89.95
99 reviews with an average rating of 4.6 out of 5 stars
REI Co-opLightweight Half-Zip Base Layer Top - Women's
$44.95
0 reviews
Top Rated
SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men's
$62.93 - $90.00
50 reviews with an average rating of 4.6 out of 5 stars
REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Men's
$39.95
0 reviews
JanjiGroundwork Long Bra
$68.00
8 reviews with an average rating of 4.1 out of 5 stars
Top Rated
IcebreakerMerino 260 Tech Long-Sleeve Crewe Thermal Top - Men's
$36.83 - $125.00
51 reviews with an average rating of 4.7 out of 5 stars
Top Rated
Icebreaker260 Merino Tech Thermal Leggings with Fly - Men's
$125.00
48 reviews with an average rating of 4.5 out of 5 stars
Top Rated
SmartwoolIntraknit Thermal Merino Base Layer Quarter-Zip Top - Men's
$97.93 - $140.00
9 reviews with an average rating of 4.9 out of 5 stars
TerryCyclo Brief 2.0 Underwear Bottoms - Women's
$59.95
0 reviews
TerryAria Liner Shorts - Women's
$69.95
22 reviews with an average rating of 4.3 out of 5 stars
Top Rated
Arc'teryxIonia Merino Wool Base Layer Hoody - Men's
$140.00
49 reviews with an average rating of 4.9 out of 5 stars
rabbitUtiliBRA-vo Sports Bra
$50.00 - $55.00
17 reviews with an average rating of 4.4 out of 5 stars

1–30 of 591 products

Sort: Best Match

Related Expert Advice articles

What material is best?

Wool is moisture-wicking and odor-resistant, while synthetic fabrics are more durable and less expensive.

Match the temp to the trek

Lightweight layers are best for moderate to cool temperatures. Midweight layers are best for cold temperatures. Heavyweight layers are best for below-freezing temperatures.

Find your fit

To be able to wick sweat efficiently, your next-to-skin layer needs to actually be next to your skin. A comfortably snug fit everywhere is your goal.

Read full article: How to Choose Base Layers