Skip to search results
loaded 87 results

Men's Underwear: Deals

(87 products)
Products (87)
Sort: Best Match
    REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Men's
    $49.83 - $99.95
    44 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's
    $44.83 - $89.95
    127 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    Top Rated
    REI Co-opHeavyweight Merino Base Layer Bottoms - Men's
    $49.83 - $99.95
    20 reviews with an average rating of 4.8 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    REI Co-opMidweight Long-Sleeve Base Layer Top - Men's
    $26.83 - $54.95
    204 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    SaxxVolt Breathable Mesh Boxer Briefs - Men's
    $26.73
    Save 23%
    compared to  $35.00
    8 reviews with an average rating of 4.3 out of 5 stars
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    REI Co-opMidweight Base Layer Half-Zip Top - Men's
    $29.83 - $59.95
    186 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big, Tall
    Royal RobbinsReadyDry Boxers - Men's
    $19.73
    Save 29%
    compared to  $28.00
    0 reviews
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    SmartwoolClassic Thermal Merino Crew Base Layer Top - Men's
    $68.83 - $125.00
    1537 reviews with an average rating of 4.7 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    tasc PerformanceElevation Merino Base Layer Bottoms - Men's
    $49.73 - $54.73
    Save 30% - 37%
    compared to  $79.00
    43 reviews with an average rating of 4.0 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Big, Regular
    REI OUTLET
    Top Rated
    PatagoniaCapilene Midweight Crew Base Layer Top - Men's
    $43.83 - $89.00
    91 reviews with an average rating of 4.5 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    Top Rated
    SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men's
    $53.83 - $100.00
    104 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    tasc PerformanceElevation Merino T-Shirt - Men's
    $34.73 - $54.73
    Save 30% - 56%
    compared to  $79.00
    53 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    REI OUTLET
    SmartwoolMerino Print Boxer Briefs - Men's
    $34.73
    Save 27%
    compared to  $48.00
    8 reviews with an average rating of 3.1 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    PatagoniaCapilene Midweight Zip-Neck Base Layer Top - Men's
    $48.83 - $99.00
    75 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    SmartwoolIntraknit 6" Boxer Briefs - Men's
    $36.73
    Save 26%
    compared to  $50.00
    7 reviews with an average rating of 3.1 out of 5 stars
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Men's
    $71.83 - $130.00
    56 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI Co-opHeavyweight Merino Base Layer Half-Zip Top - Men's
    $49.83 - $104.95
    27 reviews with an average rating of 4.2 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular, Big, Tall
    Top Rated
    SmartwoolClassic All Season Merino Long-Sleeve Base Layer Top - Men's
    $66.73
    Save 25%
    compared to  $90.00
    104 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Lightweight
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    ExOfficio9" GNG Sport 2.0 Boxer Briefs - Men's
    $24.73
    Save 27%
    compared to  $34.00
    536 reviews with an average rating of 4.7 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
    SmartwoolIntraknit Thermal Max Merino Quarter-Zip Base Layer Top - Men's
    $99.93 - $155.00
    0 reviews
    Underwear Weight:
    Midweight
    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
    SmartwoolClassic Thermal Merino Base Layer Hoodie - Men's
    $108.73
    Save 25%
    compared to  $145.00
    3 reviews with an average rating of 5.0 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI OUTLET
    PatagoniaCapilene Midweight Zip-Neck Long Underwear Top - Men's
    $63.73
    Save 35%
    compared to  $99.00
    75 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular
    REI OUTLET
    Top Rated
    SmartwoolClassic Thermal Merino 3/4 Base Layer Bottoms - Men's
    $62.83 - $115.00
    85 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    PatagoniaCapilene Thermal Weight Zip-Neck Base Layer Top - Men's
    $69.73
    Save 36%
    compared to  $109.00
    25 reviews with an average rating of 3.9 out of 5 stars
    Underwear Weight:
    Heavyweight
    Size Type:
    Regular
    REI OUTLET
    Mountain HardwearUp First Tech Fleece Base Layer Bottoms - Men's
    $74.73
    Save 25%
    compared to  $100.00
    3 reviews with an average rating of 4.3 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI OUTLET
    SmartwoolIntraknit Thermal Merino Base Layer Quarter-Zip Top - Men's
    $83.83 - $140.00
    19 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Men's
    $77.83 - $150.00
    208 reviews with an average rating of 4.4 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    New arrival
    SmartwoolClassic Thermal Merino Colorblock Crew Base Layer Top - Men's
    $96.73
    Save 25%
    compared to  $130.00
    0 reviews
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI OUTLET
    Top Rated
    SmartwoolClassic Thermal Merino Base Layer Quarter-Zip - Men's
    $89.73
    Save 25%
    compared to  $120.00
    56 reviews with an average rating of 4.6 out of 5 stars
    Underwear Weight:
    Midweight
    Size Type:
    Regular, Big
    REI OUTLET
  • Sale Ends Apr 5
    SmartwoolEveryday 6" Knit Boxer Briefs - Men's
    $29.73
    Save 38%
    compared to  $48.00
    17 reviews with an average rating of 2.3 out of 5 stars
    Size Type:
    Regular
    REI OUTLET
Sort: Best Match

Related Expert Advice articles