Skip to search results
loaded 138 results

Lightweight Base Layers

(138 products)
Products (138)
Remove underwear-weight filter:Lightweight
Sort: Best Match
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men's
    $29.83 - $79.95
    177 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women's
    $27.89
    Save 30%
    compared to  $39.95
    19 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's
    $29.83 - $89.95
    102 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Men's
    $27.89
    Save 30%
    compared to  $39.95
    9 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's
    $44.83 - $90.00
    121 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    REI Co-opMerino 185 Base Layer Top - Women's
    $34.83 - $69.95
    50 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Sale Ends Sep 1
    REI Co-opLightweight Half-Zip Base Layer Top - Women's
    $31.39
    Save 30%
    compared to  $44.95
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Base Layer Bottoms - Men's
    $27.89
    Save 30%
    compared to  $39.95
    11 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Crew Base Layer Top - Women's
    $20.89
    Save 30%
    compared to  $29.95
    9 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    SmartwoolClassic All-Season Merino T-Shirt - Women's
    $39.83 - $80.00
    88 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    REI Co-opLightweight Crew Base Layer Top - Infants'/Toddlers'
    $9.83 - $13.89
    Save 30% - 50%
    compared to  $19.95
    10 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Top Rated
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men's
    $44.83 - $90.00
    66 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Women's
    $39.83 - $89.95
    102 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    SmartwoolClassic All-Season Merino T-Shirt - Men's
    $39.83 - $80.00
    80 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Base Layer Bottoms - Infants'/Toddlers'
    $13.89
    Save 30%
    compared to  $19.95
    8 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    tasc PerformanceElevation Merino T-Shirt - Men's
    $49.73
    Save 37%
    compared to  $79.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    38 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    REI OUTLET
    REI Co-opMerino 185 Base Layer Bottoms - Men's
    $79.95
    129 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Crew Base Layer Top - Men's
    $20.89
    Save 30%
    compared to  $29.95
    17 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Base Layer Tights - Women's
    $27.89
    Save 30%
    compared to  $39.95
    7 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Half-Zip Base Layer Top - Men's
    $31.39
    Save 30%
    compared to  $44.95
    5 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's
    $19.83 - $79.95
    199 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Base Layer Crew Top - Kids'
    $20.89
    Save 30%
    compared to  $29.95
    12 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Top Rated
    Arc'teryxRho LT Zip-Neck Base Layer Top - Men's
    $120.00
    91 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Arc'teryxLana Merino Wool Crew Base Layer Top - Women's
    $59.93
    Save 33%
    compared to  $90.00
    4 reviews with an average rating of 2.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends Sep 1
    Top Rated
    REI Co-opLightweight Base Layer Bottoms - Kids'
    $20.89
    Save 30%
    compared to  $29.95
    9 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Arc'teryxRho Base Layer Bottoms - Women's
    $24.83 - $100.00
    17 reviews with an average rating of 4.1 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    Arc'teryxRho Zip-Neck Base Layer Top - Women's
    $79.93 - $120.00
    11 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    REI Co-opMerino 185 Base Layer Top - Women's Plus Sizes
    $34.83 - $69.95
    21 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Plus
    Top Rated
    Kari TraaRose High-Waisted Base Layer Pants - Women's
    $54.83 - $130.00
    14 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    tasc PerformanceElevation Merino Base Layer Bottoms - Women's
    $49.73
    Save 37%
    compared to  $79.00
    Members use code LABORDAY2025 for an extra 20% off at REI Outlet
    53 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    REI OUTLET
1–30 of 138 products
Sort: Best Match

Related Expert Advice articles