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Women's Lightweight Base Layer Tops

(35 products)
Products (35)
Sort: Best Match
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's
    $49.83 - $74.99
    Save 25% - 50%
    compared to  $100.00
    100 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends May 25
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's
    $59.89
    Save 25%
    compared to  $79.95
    246 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Sale Ends May 25
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women's
    $33.69
    Save 25%
    compared to  $44.95
    38 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends May 25
    Top Rated
    REI Co-opLightweight Half-Zip Base Layer Top - Women's
    $37.39
    Save 25%
    compared to  $49.95
    16 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends May 25
    REI Co-opMerino 185 Base Layer Top - Women's
    $52.39
    Save 25%
    compared to  $69.95
    67 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Text reads: ‘Anniversary Sale 2026. 25% off’ over a collage of Smartwool long-sleeve shirts and colorful socks.

    Save 25% on all Smartwool clothing

    Top Rated
    SmartwoolClassic All-Season Merino Quarter-Zip Base Layer Top - Women's
    $69.73
    Save 26%
    compared to  $95.00
    6 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
  • Sale Ends May 25
    Top Rated
    REI Co-opLightweight Crew Base Layer Top - Women's
    $26.19
    Save 25%
    compared to  $34.95
    30 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends May 25
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Women's
    $67.39
    Save 25%
    compared to  $89.95
    112 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Sale Ends May 25
    SmartwoolClassic All-Season Merino T-Shirt - Women's
    $71.19
    Save 25%
    compared to  $95.00
    110 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Arc'teryxSatoro Merino Wool Crew Neck Long-Sleeve Base Layer Top - Women's
    $95.73
    Save 20%
    compared to  $120.00
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    REI OUTLET
    tasc PerformanceElevation Merino T-Shirt - Women's
    $46.73
    Save 40%
    compared to  $79.00
    95 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
  • Sale Ends May 25
    Icebreaker125 Cool-Lite Merino Blend Sphere III Scoop T-Shirt - Women's
    $67.49
    Save 25%
    compared to  $90.00
    28 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
  • Sale Ends May 25
    Top Rated
    Icebreaker200 Oasis Long-Sleeve Half-Zip Base Layer Top - Women's
    $86.19 - $97.49
    Save 25%
    compared to  $115.00 - $130.00
    42 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    Arc'teryxRho Hoody Base Layer Top - Women's
    $79.83
    Save 42%
    compared to  $140.00
    42 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
    Top Rated
    Black DiamondSolution 150 Merino Base Layer Crew Top - Women's
    $99.73
    Save 26%
    compared to  $135.00
    23 reviews with an average rating of 4.9 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    Arc'teryxRho Zip-Neck Base Layer Top - Women's
    $120.00
    52 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends May 25
    Kari TraaSmekker Half-Zip Base Layer Top - Women's
    $97.99
    Save 30%
    compared to  $140.00
    21 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Arc'teryxLana Merino Wool Base Layer Tank Top - Women's
    $80.00
    4 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Icebreaker125 ZoneKnit Long-Sleeve Crewe Base Layer Thermal Top - Women's
    $93.73
    Save 25%
    compared to  $125.00
    10 reviews with an average rating of 4.1 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Black DiamondSolution 150 Quarter-Zip Hoody - Women's
    $99.73
    Save 31%
    compared to  $145.00
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Helly HansenHH Durawool Base Layer T-Shirt - Women's
    $56.73
    Save 29%
    compared to  $80.00
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
  • Sale Ends May 25
    Kari TraaAlma T-Shirt - Women's
    $55.99
    Save 30%
    compared to  $80.00
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Icebreaker125 ZoneKnit Crewe Base Layer Shirt - Women's
    $84.73
    Save 26%
    compared to  $115.00
    1 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Kari TraaSmekker Half-Zip Base Layer Top - Women's
    $89.73
    Save 30%
    compared to  $130.00
    21 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Kari TraaFierce Long-Sleeve Base Layer Top - Women's
    $45.73
    Save 30%
    compared to  $66.00
    1 reviews with an average rating of 3.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Helly HansenHH Durawool Crew Long-Sleeve Shirt - Women's
    $59.73
    Save 33%
    compared to  $90.00
    2 reviews with an average rating of 2.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
  • Limited time only! The R E I Co-op Mastercard.

    Get $130 in value

    When approved for the REI Co-op Mastercard by May 25, you’ll get $30 in card rewards. Plus, you can earn a $100 REI gift card after your first non-REI purchase within 60 days from account opening. Terms apply.

  • Sale Ends May 25
    IcebreakerSiren Sweetheart Long Underwear Top - Women's
    $63.69
    Save 25%
    compared to  $85.00
    30 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Kari TraaSmekker Long-Sleeve Base Layer Top - Women's
    $83.73
    Save 30%
    compared to  $120.00
    4 reviews with an average rating of 3.8 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Helly HansenHH LIFA Crew Base Layer Top - Women's
    $50.00
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    Arc'teryxLana Merino Wool Crew Base Layer Top - Women's
    $90.00
    8 reviews with an average rating of 3.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
1–30 of 35 products
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