Long Sleeve Underwear
(197 products)- REI Co-opMidweight Long-Sleeve Base Layer Top - Men'sTop Rated$37.93 - $54.95Underwear Weight:MidweightSize Type:Regular, Big, Tall
- REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Men's$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Big, Tall
- REI Co-opHeavyweight Merino Base Layer Half-Zip Top - Women'sTop Rated$72.93 - $104.95Underwear Weight:HeavyweightSize Type:Regular, Plus
- REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Women's$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Plus
- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's$79.95Underwear Weight:LightweightSize Type:Regular
- IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Men'sTop Rated$69.93 - $120.00Underwear Weight:MidweightSize Type:Regular, Big
- REI Co-opMidweight Long-Sleeve Base Layer Top - Women's$54.95Underwear Weight:MidweightSize Type:Regular, Plus
- SmartwoolClassic Thermal Merino Crew Base Layer Top - Women'sTop Rated$125.00Underwear Weight:MidweightSize Type:Regular, Plus
- SmartwoolClassic Thermal Merino Crew Base Layer Top - Men'sTop Rated$125.00Underwear Weight:MidweightSize Type:Regular, Big
- REI Co-opMidweight Base Layer Half-Zip Top - Men'sTop Rated$41.93 - $59.95Underwear Weight:MidweightSize Type:Regular, Big, Tall
- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men'sTop Rated$79.95Underwear Weight:LightweightSize Type:Regular, Big
- PatagoniaCapilene Midweight Crew Base Layer Top - Men'sTop Rated$61.93 - $89.00Underwear Weight:MidweightSize Type:Regular, Big
- SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's$100.00Underwear Weight:LightweightSize Type:Regular, Plus
- REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men'sTop Rated$62.93 - $89.95Underwear Weight:LightweightSize Type:Regular, Big
- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's Plus Sizes$49.93Save 37%compared to  $79.95Underwear Weight:LightweightSize Type:Plus
- tasc PerformanceElevation Merino T-Shirt - Women's$54.73Save 30%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, PlusREI OUTLET
- REI Co-opMidweight Base Layer Half-Zip Top - Women's$59.95Underwear Weight:MidweightSize Type:Regular, Plus
- IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Women'sTop Rated$69.93 - $120.00Underwear Weight:MidweightSize Type:Regular, Plus
- REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Women'sTop Rated$44.95Underwear Weight:LightweightSize Type:Regular, Plus
- SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Men'sTop Rated$130.00Underwear Weight:MidweightSize Type:Regular, Big
Get $130 in value
$30 in card rewards are yours when approved for the REI Co-op Mastercard by Mar 9. Plus, you can earn a $100 REI gift card after your first purchase. Terms apply.
Apply now- Arc'teryxRho LT Crew Neck Base Layer Top - Men'sTop Rated$100.00Underwear Weight:LightweightSize Type:Regular, Big
- SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Women'sTop Rated$130.00Underwear Weight:MidweightSize Type:Regular, Plus
- REI Co-opLightweight Half-Zip Base Layer Top - Women'sTop Rated$49.95Underwear Weight:LightweightSize Type:Regular, Plus
- tasc PerformanceElevation Merino T-Shirt - Men's$34.73 - $54.73Save 30% - 56%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, BigREI OUTLET
- Arc'teryxRho LT Zip-Neck Base Layer Top - Men's$120.00Underwear Weight:LightweightSize Type:Regular, Big
- REI Co-opMidweight Base Layer Crew Top - Kids'Top Rated$34.95Underwear Weight:MidweightSize Type:Regular
- Kari TraaEmbla Wool Long-Sleeve Base Layer Top - Women's$62.93 - $90.00Underwear Weight:UltralightweightSize Type:Regular
- REI Co-opLightweight Long-Sleeve Crew Base Layer Top - Men's$44.95Underwear Weight:LightweightSize Type:Regular, Big, Tall
- Helly HansenLIFA Merino Midweight Graphic Crew Base Layer - Women's$79.73Save 27%compared to  $110.00Underwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men'sTop Rated$66.93 - $100.00Underwear Weight:LightweightSize Type:Regular, Big





































































































































































