Icebreaker's versatile, go-anywhere shirt made from breathable 100% merino wool jersey, the 200 Oasis Long Sleeve Crewe is the best-selling base layer top.

Icebreaker's versatile, go-anywhere shirt made from breathable 100% merino wool jersey, the 200 Oasis Long Sleeve Crewe is the best-selling base layer top.

Icebreaker's versatile, go-anywhere shirt made from breathable 100% merino wool jersey, the 200 Oasis Long Sleeve Crewe is the best-selling base layer top.

A warmer, midweight version of our best-selling Oasis, the 260 Tech Long Sleeve Half Zip is a go-to piece for winter layering, made with 100% merino wool.

Midweight base layer bottoms perfect for skiing, winter hiking, or cold-weather layering, the 260 Tech Leggings are a warmer version of our best-selling Oasis Leggings, made with 100% merino wool.

An incredibly warm merino wool base layer with a unique jacquard pattern, the Merino 260 Vertex Long Sleeve Crewe On-Piste is a go-to piece for winter layering—ideal for skiing, snowshoeing and other cold-weather pursuits. The simple line pattern references the delicate curves of ski track arcing down the mountain.

Comfortable, considered and eco-friendly, celebrate the future of sustainable sportswear with ODLO’s Women’s ACTIVE WARM ECO Long-Sleeve base layer top.

Crafted from recycled polyester fibres to reduce its carbon footprint, this next generation base layer is ideal for alpine pursuits thanks to its warm and breathable qualities. 

Warm, dry and sustainable – welcome to the future of sportswear with ODLO’s Women’s ACTIVE WARM ECO Half-Zip Turtleneck base layer top.

Crafted from 100 percent recycled materials, this versatile base layer brings an environmental ethos to the core of your sportswear.

The enhanced thermoregulation and exceptional comfort delivered by the ACTIVE X-WARM ECO Long-Sleeve base layer top make this versatile garment a winter-weather essential for active women.

Using soft insulation pads to protect particularly sensitive areas of the body from the cold, the ACTIVE X-WARM range provides excellent insulation as the cold sets in, while excellent moisture management properties guarantee you stay warm and dry at all times. 

A classic, all-around 100% recycled polyester baselayer. The smooth, soft face makes for easy layering. Hollow-core yarns and a diamond-grid back trap warm air, wick moisture and dry fast. HeiQ® Mint odor control keeps things fresh. Made in a Fair Trade Certified™ factory.

Smartwool's Women's Classic All-Season Merino Base Layer Bottoms are the perfect layer to put on for your warm-weather adventures.

Made of lightweight, breathable Merino, these base layer pants have an updated fit that improves functionality while enhancing aesthetics for a wide range of body shapes. We wrapped our super-soft, responsibly sourced Merino around a nylon core to give it added durability, so it can keep up with you.

Wherever you're going and whatever you're doing, our lightest weight base layer bottoms are perfect for adventures during all seasons.

An all-season favorite, the Classic All-Season Merino Base Layer Long Sleeve can be sported as a base layer in the fall or summer when it's time to go backpacking.

This base layer features Core Spun technology—which features Merino wrapped around a nylon core for added durability while still keeping the comfort of ultra-soft, responsibly sourced Merino next to skin.

Smartwool's Raglan sleeves eliminate shoulder seams for perfect comfort under a pack, and smooth merrow stitching wraps from side to front to keep you looking as good as you feel.

We've updated the fit of our Women's Classic Thermal Merino Base Layer 1/4 Zip to improve functionality while also enhancing aesthetics. As one of our heaviest base layer tops and best base layers for cold weather, this garment uses 100% responsibly sourced Merino wool, shoulder panels, and a flatlock seam construction to help minimize chafing as well as help keep you comfortable and temperature-regulated as you enjoy high-intensity skiing, hiking, running, and more.

Meet the new and improved Women's Classic Thermal Merino Base Layer Crew. We've updated this 100% Merino wool fan favorite with new color options and an enhanced fit to improve functionality while elevating aesthetics. The addition of shoulder panels and its flatlock seam construction help prevent chafing and increase your comfort level. Add one of our best base layers for cold weather to your winter wardrobe and experience the difference the next time you go skiing, hiking, climbing, or biking.

100% Merino. 100% capable. Smartwool's Women's Classic Thermal Merino Base Layer is always ready for what's ahead and what's next.

With a fit updated to improve functionality while enhancing aesthetics for a range of body shapes and a flatlock seam construction designed to minimize chafing, comfort is never in question.

Get yourself a pair or two of our best base layer pants and conquer the cold with more confidence than ever.

Meet the new and improved Women's Merino 250 Base Layer Crew.

Smartwool have updated this 100% Merino wool fan-favorite with an enhanced fit to improve functionality while elevating aesthetics. The addition of shoulder panels its flatlock seam construction helps prevent chafing and increases your comfort level.

Add one of Smartwool's best base layers for cold weather to your winter wardrobe and experience the difference the next time you go skiing, hiking, climbing, or biking.

An ultra-comfy underwear bottom for everyday wear, the Siren Hipkini features ultra-lightweight corespun merino blend fabric that’s durable, stretchy and incredibly soft.

A soft and stretchy tank top with a sleek, feminine design for everyday layering comfort, the Siren Tank features our durable and incredibly soft corespun merino wool blend fabric.