Underwear

Our cutting-edge Intraknit™ Merino 200 Bottoms are here to help you warm up to cold weather. 3D-knit articulation adds an enhanced fit and helps keep you as mobile as ever. Merino Sport Yarn helps provide quicker dry times, odor resistance, and durability, while targeted knit insulation and ventilation help keep you warm and dry. No matter if you're running, skiing, or cold-weather adventuring, these men's base layer pants are up for the challenge.

We've updated the fit of our Men's Merino 250 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. Features 100% Merino wool fabric made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance Fit updated to improve functionality while enhancing aesthetics Shoulder panels eliminate top shoulder seams Flatlock seam construction designed to minimize chafing

Meet the better-than-ever Men's Merino 250 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. Shoulder panels eliminate top shoulder seams and a flatlock seam construction helps prevent chafing. 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.

The coldest days call for the smartest gear. The Merino 250 Base Layer Bottom fits the bill with our heaviest weight and warmest fabric, a covered elastic waistband and flatlock seam construction to help keep you comfortable from the first tracks to the last chair.

Before you head out on your yurt trip or go for an afternoon skate-ski, throw on our Men's Merino Sport 250 Bottom and enjoy Merino comfort and performance. Our minimal Merrow seam construction provides superior durability while keeping super-soft material next to skin. Our warmest Merino/poly blend helps move moisture, dries quickly, and holds its shape, no matter how sweaty you get during your expedition. Gender-specific, body-mapped panels of lighter fabric offer additional breathability, while reflective elements help provide additional visibility in low-light conditions.

Zip up and head out this winter with a layer that provides warmth, comfort, and performance—the Men's Merino Sport 250 Long Sleeve 1/4 Zip tee. Our warmest Merino/poly blend will help move moisture away from skin as you heat up, and it will dry quickly and hold its shape no matter how sweaty you get during your workouts. For even more breathability, we've added gender-specific, body-mapped panels of mesh fabrics. Minimal Merrow seam construction provides superior durability while keeping super-soft material against your skin, and thumb loops provide a secure fit.

The weather may be cold outside, but you don't let that keep you from getting out and working hard. And if you're looking for a trustworthy companion on your adventures, throw on a layer that won't let you down—the Men's Merino Sport 250 Long Sleeve Crew. Merino Sport fabric has all the benefits of Merino—breathability, temperature regulation, and odor resistance—with the added quick dry time and durability of polyester. Gender-specific, body-mapped panels of mesh fabric provide even more breathability, while integrated thumbholes provide additional coverage as you head out and take on the winter.

Whether you're running in frigid temps or skate-skiing in blustery winds, our Men's Merino Sport 250 Wind Boxer Brief keeps you comfortably covered. Smartwool's warmest Merino/poly-engineered material helps move moisture, dries quickly, and holds its shape during your highest-intensity activities. A windproof front panel provides increased protection as temps drop. And minimal Merrow seam construction provides superior durability while keeping super-soft Merino next to skin.

/ HOW IT FITS Semi-Compression Fit: hugs the body but is never restrictive. / MADE FOR Up-tempo training, cardio, and recreational activity. This style is a stealth superhero, incorporating comfort, support, and security to enhance your movement. / BUILT IN TECH Performance based BallPark Pouch™, Three-D Fit™, Flat Out Seams™.

/ HOW IT FITS Relaxed Fit: uber-soft, with a fly. / MADE FOR The guy who wants the best for his boys. Our softest collection, offering all-day comfort for work or travel. Updated this season to include a trunk. / BUILT IN TECH BallPark Pouch™, Three-D Fit™, Flat Out Seams™.

/ HOW IT FITS Slim Fit: no fly. / MADE FOR The guy who wants to look good while he works out. Volt is cut from a breathable pin-dot mesh, perfect for high-aerobic training or sport activities. / BUILT IN TECH BallPark Pouch™, Three-D Fit™, Flat Out Seams™

Practical both as a midweight baselayer and a lightweight fleece, our easy-pack Flux Pull-On is perfect for longer multi-day climbing and trekking trips when you want to stay warm, dry and active. Our new Flux Pull-On provides versatile fast-wicking insulation. Designed to keep you dry when you work so you can stay warm when you stop, it is built from Thermic™ single jersey knit with a brushed back for outstanding comfort. It also uses low-profile flatlock seams to provide friction-free comfort next to the skin, even during extreme physical activity. The deep-venting YKK VISLON® half-zip enables you to adjust the warmth to match the activity and the unobtrusive thumb loops keep the layer secure and draught-free. To help with the repeated work-rest cycles of mountain recreation, it also features Polygiene® STAYS FRESH technology, which reduces odour-causing bacteria by 99% for the entire life of the garment. Whether you're escaping for a weekend of bothy-hopping or moving fast from hut to hut, the new Flux Pull-On has the fit, the fabric and the features to keep you comfortable and fresh.

ACTIVE SPORT ankle length base layer bottom with elastic waistband. ACTIVE style for men.

ACTIVE SPORT, lightweight technical base layer crew neck top. ACTIVE style for men.

ACTIVE SPORT base layer zip top for high level activities. Men ACTIVE style.

MERINO BLEND base layer zip top. Soft on the inside, warm on the outside. MULTI style for men.

Icebreaker's lightest-weight long sleeve base layer tops are the ideal second skin to keep you comfortable throughout your physical pursuits. Made with breathable and insulating 150gm corespun merino, the Zone Long Sleeve Half Zip is perfect for year-round adventures. Whether you are running off-road, biking or just training around the city, it has got just enough LYCRA® to maximise flexibility while its next-to-skin comfort makes it a must have layering piece. Strategically placed merino mesh offers thermo-regulation, while flatlock seams prevent chafing during vigorous movement.

The slim-fit 175gm Everyday Boxers With Fly are go-to men's merino wool underwear for any day, anywhere.

A perfect base layer on cooler morning commutes or year-round travel. Made from breathable merino rib, Icebreaker's 175gm Everyday Leggings move with you, keeping you warm in cooler weather and cool in warmer conditions. A naturally odour resistant fabrication allows for multi-day wear, ideal for journeys further afield. INSEAM: Large = 77.2cm / 30½" FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports, Adventure BENEFITS: Comfort, Odour Resistant, Breathable, Moves with you FEATURES: Rib fabric provides stretch and comfort, Icebreaker branded brushed elastic waistband, inseam: 77.2cm/30½", size L FABRIC WEIGHT: 175 Ultralight FABRIC: 100% Merino Wool

A classic, all-purpose men’s base layer T-shirt made with soft and breathable 100% merino wool fabric, the 175 Everyday Long Sleeve Crewe is as versatile as it is comfortable.

Icebreaker's 100% merino, 200gm Everyday Bodyfit™ tops layer effortlessly under any mid and outer layers for the ultimate cool weather adventures. With seams carefully offset from the peak of your shoulder, you won't find any irritation from the straps of a heavy pack. All over flatlock seams prevent chafing and underarm gussets allow breathability where your body needs it. The Oasis Long Sleeve Half Zip is your go-to adventure staple. FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports, Adventure BENEFITS: Comfort, Odour Resistant, Breathable, Warm FEATURES: Zip neck collar for temperature regulation, offset shoulder seams prevent pack rub, flatlock seams prevent chafing, underarm gusset for comfort and mobility, drop tail hem for added coverage, center back length: 75.4cm/29¾", size L, Icebreaker tonal embroidered logo FABRIC WEIGHT: 200 Lightweight FABRIC: 100% Merino Wool

Active men’s base layer bottoms made from 100% merino wool jersey, the 200 Oasis Leggings are Icebreaker's best-selling long underwear.

Icebreaker's best-selling active baselayer bottoms made with their ultra-comfortable 100% merino jersey fabric and an updated design for improved comfort, the 200 Oasis Leggings are the perfect foundation for your everyday cold-weather layering system. The Oasis fabric is not only insulating and highly breathable, but it resists odors during extended use. The slim fit and gusseted construction provide unrestricted freedom of movement, while the brushed elastic waistband and flatlock seams throughout eliminate chafing when you’re on the move. INSEAM: Large = 78.1cm / 30¾" FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports, Adventure BENEFITS: Comfort, Odour Resistant, Breathable, Warm FEATURES: Icebreaker branded brushed elastic waistband, flatlock seams prevent chafing, gusset for comfort and mobility, inseam: 78.1cm/30¾", size L FABRIC WEIGHT: 200 Lightweight FABRIC: 100% Merino Wool

Icebreaker's best-selling active baselayer bottoms made with their ultra-comfortable 100% merino jersey fabric and an updated design for improved comfort, the 200 Oasis Leggings w/ Fly are the perfect foundation for your everyday cold-weather layering system. The Oasis fabric is not only insulating and highly breathable, but it resists odors during extended use. The slim fit and gusseted construction provide unrestricted freedom of movement, while the brushed elastic waistband and flatlock seams throughout eliminate chafing when you’re on the move. FEATURES: Updated design, Icebreaker branded brushed elastic waistband, Flatlock seams prevent chafing, Contoured pouch with functioning fly, Gusset for comfort and mobility, Inseam: 78.1cm/30¾", size L FABRIC: 100% Merino Wool

Icebreaker's classic reliable merino baselayer bottom in a mid-calf design, the 200 Oasis Legless is designed for use with ski boots, mountain boots and other high-cuff winter footwear. The updated design features a gusset for comfort and mobility, and short-leg length to eliminate uncomfortable bunching. The 100% merino jersey fabric offers super-soft, next-to-skin comfort, incredible breathability and natural odor resistance. The brushed elastic waistband and flatlock seams prevent irritation during high-intensity days outside. INSEAM: Large = 60cm / 23½" FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports, Adventure BENEFITS: Comfort, Odour Resistant, Breathable, Warm FEATURES: Icebreaker branded brushed elastic waistband, flatlock seams prevent chafing, gusset for comfort and mobility, inseam: 60cm/23½", size L FABRIC WEIGHT: 200 Lightweight FABRIC: 100% Merino Wool

A versatile men’s merino wool base layer shirt, the 200 Oasis Long Sleeve Crewe combines casual comfort with technical performance.

Our versatile, go-anywhere shirt made from breathable 100% merino wool jersey, the 200 Oasis Short Sleeve Crewe is our best-selling base layer top

A warmer midweight version of Icebreaker's best-selling Oasis Leggings, perfect for frigid days on the trails or the mountain, the updated 260 Tech Leggings feature a 100% merino wool fabric for premium softness, insulation and breathability. These odor-resistant baselayer bottoms also feature a gusseted construction for ample range of motion, and the brushed elastic waistband and flatlock stitching throughout eliminate chafing when you’re on the move. FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports, Adventure BENEFITS: Comfort, Breathable, Warm FEATURES: Icebreaker branded brushed elastic waistband, flatlock seams prevent chafing, gusset for comfort and mobility, inseam: 78.1cm/30¾", size L FABRIC WEIGHT: 260 Midweight FABRIC: 100% Merino Wool

Midweight men’s merino wool base layer leggings perfect for skiing, winter hiking or cold-weather layering, the 260 Tech Leggings are technical long underwear bottoms that feature a gusseted construction and breathable, odor-resistant fabric.

A warmer midweight version of Icebreaker's best-selling Oasis Leggings, perfect for frigid days on the trails or the mountain, the updated 260 Tech Leggings w/ Fly feature a 100% merino wool fabric for premium softness, insulation and breathability. These odor-resistant baselayer bottoms also feature a gusseted construction for ample range of motion, and the brushed elastic waistband and flatlock stitching throughout eliminate chafing when you’re on the move. FIT: Slim LAYER: Base Layers BEST FOR: Snow Sports BENEFITS: Comfort, Breathable, Warm FEATURES: Updated design, flatlock seams prevent chafing, contoured pouch with functioning fly, Icebreaker branded brushed elastic waistband, gusset for comfort and mobility FABRIC WEIGHT: 260 Midweight FABRIC: 100% Merino Wool PRODUCT WEIGHT: Medium = 243 g / 8.57 oz