Skip to search results
loaded 198 results
Long Sleeve Base Layers
(198 products)Products (198)
Sort: Best Match
- SmartwoolIntraknit Thermal Merino Pattern Crew Base Layer Top - Women's$96.73Save 25%compared to  $130.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolClassic Thermal Merino Base Layer Quarter-Zip - Men'sTop Rated$89.73Save 25%compared to  $120.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:Regular, BigREI OUTLET
- Free CountryForce Grid Fleece Base Layer Top - Women's$34.73Save 36%compared to  $55.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:RegularREI OUTLET
- REI Co-opMerino Midweight Base Layer Crew Top - Kids'Top Rated$49.95Underwear Weight:MidweightSize Type:Regular
- Arms of Andes160 Ultralight Alpaca Wool Long-Sleeve Base Layer Shirt - Men's$85.00Underwear Weight:UltralightweightSize Type:Regular, Big
- PatagoniaCapilene Thermal Weight Zip-Neck Top - Men's$109.00Underwear Weight:HeavyweightSize Type:Regular
- PatagoniaCapilene Midweight Zip-Neck Base Layer Top - Women's$74.73Save 24%compared to  $99.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolIntraknit Thermal Max Merino Base Layer Pattern Hoodie - Women's$123.73Save 25%compared to  $165.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletSize Type:RegularREI OUTLET
- SmartwoolClassic Thermal Merino Base Layer Hoodie - Kids'$51.73Save 31%compared to  $75.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men's Tall SizesTop Rated$79.95Underwear Weight:LightweightSize Type:Tall, Big
- SmartwoolIntraknit Thermal Merino Pattern Crew Base Layer Top - Women's$59.83Save 53%compared to  $130.00Underwear Weight:MidweightSize Type:Regular
- PatagoniaCapilene Thermal Weight Long Underwear Crew Top - Men's$99.00Underwear Weight:HeavyweightSize Type:Regular
- SmartwoolIntraknit Active Base Layer Crew Shirt - Women's$76.73Save 30%compared to  $110.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Free CountryMicrotech Heat Cocaber Base Layer Top - Men's$21.73Save 45%compared to  $40.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:BigREI OUTLET
- SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Men's$92.73Save 28%compared to  $130.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:Regular, BigREI OUTLET
- HalfdaysJohnson Base Layer Top - Women's$49.83Save 41%compared to  $85.00Underwear Weight:UltralightweightSize Type:Plus
- SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Men's$130.00Underwear Weight:MidweightSize Type:Regular, Big
- Helly HansenLifa Merino Midweight Graphic Base Layer Top - Women'sTop Rated$79.73 - $82.73Save 24% - 27%compared to  $110.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SmartwoolIntraknit Thermal Merino Base Layer Colorblock Crew - Men's$96.73Save 25%compared to  $130.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:Regular, BigREI OUTLET
- SmartwoolIntraknit Thermal Merino Crew Base Layer Top - Women's$130.00Underwear Weight:MidweightSize Type:Regular
- REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men's Tall SizesTop Rated$89.95Underwear Weight:LightweightSize Type:Tall, Big
- ArtilectBoulder 125 Crew Long-Sleeve Base Layer Top - Women's$75.73Save 36%compared to  $120.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:RegularREI OUTLET
- SmartwoolIntraknit Thermal Merino Pattern Crew Base Layer Top - Men's$75.73Save 41%compared to  $130.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:BigREI OUTLET
- SpraywayEffra Hoody Base Layer Top - Women's$49.73Save 28%compared to  $69.95Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize Type:Regular, PlusREI OUTLET
- SmartwoolIntraknit Active Base Layer Crew Shirt - Men's$81.73Save 25%compared to  $110.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:Regular, BigREI OUTLET
- Helly HansenLIFA Merino Midweight Half-Zip Base Layer Top - Women's$79.73 - $82.73Save 24% - 27%compared to  $110.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Free CountryForce Grid Fleece Base Layer Top - Men's$29.73Save 33%compared to  $45.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:BigREI OUTLET
- Arc'teryxRho Heavyweight Zip-Neck Base Layer Top - Men's$112.73Save 19%compared to  $140.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize Type:BigREI OUTLET
- Terramar2.0 Cloud Nine Midweight Performance Thermal Turtleneck - Women's$32.73Save 31%compared to  $48.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Helly HansenHH Durawool Crew Long-Sleeve Base Layer - Women's$90.00Underwear Weight:LightweightSize Type:Regular
61–90 of 198 products
Sort: Best Match