Base Layer Tops: Deals
(139 products)- HalfdaysJohnson Base Layer Top - Women's$49.83Save 41%compared to $85.00Underwear Weight:UltralightweightSize Type:Plus
- SpraywayEffra Crew Base Layer Top - Women's$36.73Save 26%compared to $49.95Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize Type:Regular, PlusREI 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
- Free CountryMicrotech Heat Cocaber Base Layer Top - Women's$34.73Save 30%compared to $50.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:LightweightSize Type:RegularREI 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
- Terramar3.0 Thermawool Half-Zip Base Layer Top - Women's$56.73Save 24%compared to $75.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize 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
- SmartwoolIntraknit Thermal Merino Pattern Crew Base Layer Top - Women's$59.83Save 53%compared to $130.00Underwear Weight:MidweightSize Type:Regular
- Kari TraaLilja Long-Sleeve Base Layer Top - Women's$49.73Save 24%compared to $66.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize Type:RegularREI OUTLET
- SpraywayEffra Jacket Base Layer Top - Women's$46.73Save 28%compared to $64.95Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize Type:Regular, PlusREI OUTLET
- 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
- Picture Organic ClothingNangha Base Layer Top - Men's$44.83Save 50%compared to $90.00Underwear 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
- Kari TraaRose Base Layer Hoodie - Women's$97.73Save 24%compared to $130.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:HeavyweightSize 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 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
- Kari TraaFloke Long-Sleeve Base Layer Top - Women's$74.73Save 25%compared to $100.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- Ortovox185 Merino Rock'n'wool Base Layer Top - Women's$49.83Save 50%compared to $100.00Underwear Weight:MidweightSize Type:Regular
- Terramar2.0 Ultra Merino Turtleneck Base Layer Top - Women's$52.73Save 29%compared to $75.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI OUTLET
- SeirusHeatwave All Season Reversible Long-Sleeve Base Layer Top - Women's$36.83Save 50%compared to $75.00Underwear Weight:LightweightSize Type:Regular
- 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
- 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
- Terramar2.0 Cloud Nine Midweight Performance Base Layer Scoop Shirt - Women's$29.73Save 33%compared to $45.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize 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
- Kari TraaRose Light Half-Zip Base Layer Top - Women's$89.73Save 25%compared to $120.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:RegularREI 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
- ArtilectDarkhorse 185 Zoned Crew Base Layer Top - Men'sTop Rated$109.73Save 31%compared to $160.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:Regular, 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
- 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
- CotopaxiLiso Base Layer Top - Men'sTop Rated$44.73Save 31%compared to $65.00Members use code OUT4JUL25 for $20 off $100+ at REI OutletUnderwear Weight:MidweightSize Type:BigREI OUTLET