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Underwear

(489 products)
Products (489)
Sort: Best Match
    REI Co-opMerino Bikini Underwear - Women's
    $27.95
    64 reviews with an average rating of 4.1 out of 5 stars
    Size Type:
    Regular, Plus
    REI Co-opMerino Boxer Briefs - Men's
    $39.95
    121 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opMerino Bralette
    $44.95
    204 reviews with an average rating of 4.6 out of 5 stars
    Bra Support:
    Low Impact
    Support Style:
    Encapsulation
    Fabric:
    48% merino wool/32% TENCEL lyocell/15% nylon/5% LYCRA spandex
    Top Rated
    SaxxQuest Quick-Dry Boxer Briefs - Men's - Package of 2
    $35.83 - $66.00
    36 reviews with an average rating of 4.7 out of 5 stars
    Size Type:
    Big, Regular
    TerramarPerformance Briefs - Men's - Package of 3
    $19.73
    Save 34%
    compared to  $30.00
    Members use code LABORDAY26 to save an extra 20% thru 9/7.
    5 reviews with an average rating of 4.0 out of 5 stars
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Women's
    $29.83
    Save 66%
    compared to  $89.95
    114 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    SmartwoolClassic Thermal Merino Base Layer Bottoms - Women's
    $59.83 - $125.00
    293 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    REI Co-opMerino Hipster Underwear - Women's
    $29.95
    60 reviews with an average rating of 3.9 out of 5 stars
    Size Type:
    Regular, Plus
    Top Rated
    SaxxQuest Quick-Dry Boxer Briefs - Men's
    $36.00
    48 reviews with an average rating of 4.6 out of 5 stars
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Women's
    $59.83 - $125.00
    459 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Men's
    $59.83 - $125.00
    332 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    SmartwoolMerino Bikini Underwear - Boxed - Women's
    $35.00
    5 reviews with an average rating of 3.0 out of 5 stars
    Size Type:
    Regular
    Top Rated
    REI Co-opMidweight Base Layer Half-Zip Top - Men's
    $19.83
    Save 66%
    compared to  $59.95
    202 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI Co-opActive Bralette 2.0
    $35.95
    137 reviews with an average rating of 4.3 out of 5 stars
    Bra Support:
    Low Impact
    Support Style:
    Encapsulation
    Fabric:
    86% polyester/14% spandex mesh
    REI Co-opActive Briefs - Women's
    $19.95
    43 reviews with an average rating of 4.1 out of 5 stars
    Size Type:
    Regular, Plus
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's
    $29.83
    Save 66%
    compared to  $89.95
    149 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    SmartwoolMerino Boxer Briefs - Boxed - Men's
    $50.00
    6 reviews with an average rating of 3.2 out of 5 stars
    Size Type:
    Regular, Big
    SmartwoolClassic All-Season Merino T-Shirt - Men's
    $39.83 - $95.00
    144 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Women's
    $59.83 - $130.00
    89 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus
    REI Co-opMerino Boxers - Men's
    $39.95
    87 reviews with an average rating of 4.4 out of 5 stars
    Size Type:
    Big, Regular
    ExOfficioGive-N-Go 2.0 Sport Mesh Thong Underwear - Women's
    $16.73
    Save 30%
    compared to  $24.00
    Members use code LABORDAY26 to save an extra 20% thru 9/7.
    155 reviews with an average rating of 3.9 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    SENIQEverform Merino Wool All-Season Long-Sleeve Base Layer Shirt - Women's
    $108.00
    0 reviews
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    New arrival
    Terramar1.0 All Season Merino Crew Base Layer Top - Women's
    $36.73
    Save 33%
    compared to  $55.00
    Members use code LABORDAY26 to save an extra 20% thru 9/7.
    0 reviews
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men's
    $29.83 - $100.00
    124 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • Limited time only! The R E I Co-op Mastercard.

    $130 in value

    Get $30 in card rewards when approved by Sep 7. Plus, earn a $100 REI gift card after first qualifying purchase. Terms apply.

  • Sale Ends Sep 7
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Men's
    $33.69
    Save 25%
    compared to  $44.95
    49 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Men's
    $79.93 - $120.00
    88 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    JanjiGroundwork Long Bra
    $53.93 - $80.00
    31 reviews with an average rating of 3.8 out of 5 stars
    Bra Support:
    Medium Impact
    Support Style:
    Compression / Encapsulation
    Fabric:
    68% nylon/32% spandex
    REI Co-opActive Hipster Underwear - Women's
    $19.95
    45 reviews with an average rating of 3.9 out of 5 stars
    Size Type:
    Regular, Plus
  • Sale Ends Sep 7
    Top Rated
    REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women's
    $33.69
    Save 25%
    compared to  $44.95
    48 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Plus
  • Sale Ends Sep 7
    Top Rated
    BrooksChaser Padded Bra
    $45.49
    Save 30%
    compared to  $65.00
    44 reviews with an average rating of 4.7 out of 5 stars
    Bra Support:
    Medium Impact
    Support Style:
    Encapsulation
    Fabric:
    75% nylon/25% spandex
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