The most trusted
base layers
since 1999.

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One base.
All bases covered.

It’s the #1 base layer on the U.S. market for a reason. Our Classic Thermal styles are your everywhere wear—ready to perform at the highest level or kickback at the lowest. No matter how you spend your time outside, we have a base layer built to keep you out there.

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Best on the market!– Brad from Denver

Meet the better-than-ever Classic Thermal Merino Base Layer Crew. We've updated this 100% Merino wool fan-favorite with new colors and a new fit to improve functionality while enhancing aesthetics.

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Classic ThermalBase Layer
FEATURES
Cold weather comfort.– Sam from Boston

Meet the better-than-ever Classic Thermal Merino Base Layer Crew. We've updated this 100% Merino wool fan-favorite with new colors and a new fit to improve functionality while enhancing aesthetics.

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Classic ThermalBase Layer
FEATURES
Men's Base Layer Women's Base Layer
2 women wearing Smartwool base layers

go far. feel good.™


We think you’ll love our award-winning running socks, but don’t just take it from us. Hear it from the Smartwool community.

Gear up to go farther.


No matter how you get outside, it’s easy to find your best Merino wool base layer for you with Smartwool.
Whether you need a lightweight Merino wool base layer for year-round adventures or our warmest Smartwool® base layer for every winter outing, we have the comfort you need to go farther. Shop women’s Smartwool® base layers, men’s Smartwool® base layers, and the entire Smartwool® Intraknit™ base layer collection today and explore forever.

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