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Underwear

(508 products)
Products (508)
Sort: Best Match
    REI Co-opActive Briefs - Women's
    $19.95
    40 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular, Plus
    REI Co-opMerino Bikini Underwear - Women's
    $27.95
    58 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular, Plus
    ExOfficioGive-N-Go 2.0 Full-Cut Brief Underwear - Women's
    $16.73
    Save 30%
    compared to  $24.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    948 reviews with an average rating of 4.3 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    New arrival
    SmartwoolMerino Bikini Underwear Boxed - Women's
    $35.00
    0 reviews
    Size Type:
    Regular
    REI Co-opMerino Boxer Briefs - Men's
    $39.95
    114 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular, Big
    ExOfficioGive-N-Go 2.0 Bikini Briefs - Women's
    $14.73
    Save 26%
    compared to  $20.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    1904 reviews with an average rating of 4.4 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    REI Co-opEveryday Boxer Briefs - Men's
    $24.95
    159 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular, Big
    REI Co-opMerino Hipster Underwear - Women's
    $29.95
    52 reviews with an average rating of 3.9 out of 5 stars
    Size Type:
    Regular, Plus
    REI Co-opActive Bikini Underwear - Women's
    $19.95
    53 reviews with an average rating of 3.4 out of 5 stars
    Size Type:
    Regular, Plus
    Top Rated
    ExOfficioGive-N-Go 2.0 Boxer Briefs - Men's
    $19.73
    Save 34%
    compared to  $30.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    964 reviews with an average rating of 4.6 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    ExOfficioGive-N-Go Sport 2.0 Sport Mesh Bikini Briefs - Women's
    $18.73
    Save 27%
    compared to  $26.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    490 reviews with an average rating of 4.4 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    SaxxQuest Quick-Dry Boxer Briefs - Men's
    $34.00
    0 reviews
    Size Type:
    Regular, Big
    REI Co-opActive Hipster Underwear - Women's
    $19.95
    40 reviews with an average rating of 3.9 out of 5 stars
    Size Type:
    Regular, Plus
    REI Co-opMerino Boxers - Men's
    $39.95
    77 reviews with an average rating of 4.3 out of 5 stars
    Size Type:
    Regular, Big
    SaxxVibe Xtra Soft Comfort Boxer Briefs - Men's
    $24.73
    Save 27%
    compared to  $34.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    1 reviews with an average rating of 5.0 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    SaxxVolt Breathable Mesh Boxer Briefs - Men's
    $26.73
    Save 23%
    compared to  $35.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    8 reviews with an average rating of 4.3 out of 5 stars
    Size Type:
    Regular, Big
    REI OUTLET
    REI Co-opActive Thong Underwear - Women's
    $6.83 - $16.95
    25 reviews with an average rating of 4.3 out of 5 stars
    Size Type:
    Regular, Plus
    REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Men's
    $69.93 - $99.95
    39 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    REI Co-opMidweight Base Layer Bottoms - Men's
    $54.95
    100 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    REI Co-opMerino 185 Base Layer Bottoms - Men's
    $79.95
    161 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
  • The R E I Co-op Mastercard. Earn 15% total R E I rewards.

    Earn 15% in total rewards

    Get 5% on all REI Co-op purchases plus the 10% Co-op Member Reward you earn on eligible full-price purchases.



    Terms apply
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men's
    $79.95
    220 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opMerino Bralette
    $44.95
    186 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
    REI Co-opMidweight Base Layer Tights - Women's
    $54.95
    123 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Plus, Petite
    ExOfficioEveryday Hipster Underwear - Women's
    $16.73
    Save 30%
    compared to  $24.00
    Use code OUTFEB26 for $20 off when you spend $100+ at REI Outlet.
    106 reviews with an average rating of 4.2 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    REI Co-opMidweight Long-Sleeve Base Layer Top - Men's
    $37.93 - $54.95
    195 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    REI Co-opLightweight Base Layer Bottoms - Men's
    $44.95
    26 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big, Tall
    REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Women's
    $69.93 - $99.95
    43 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Plus
    REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's
    $79.95
    238 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular
    SaxxQuest Quick-Dry Boxer Briefs - Men's - Package of 2
    $61.00
    0 reviews
    Size Type:
    Regular, Big
    Kari TraaEmbla Wool Boxer Briefs - Women's
    $40.00
    3 reviews with an average rating of 2.0 out of 5 stars
    Size Type:
    Regular
1–30 of 508 products
Sort: Best Match

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