The Most Comfortable Long Underwear Bottoms 2024

Stay warm and stylish this winter season.

Thermal underwear, long underwear, long johns, or base layers, whatever you prefer to call them, they’re a great way to stay warm when the temperatures drop.

For the uninitiated, long underwear is the form-fitting base layer worn under your everyday clothes that provides an extra layer of warmth.

A high-quality pair of long underwear will not only be very comfortable to wear but also do a much better job of retaining body heat than your regular clothes could do on their own.

Additionally, most have breathable designs to keep you from overheating and moisture-wicking fabric to keep you dry.

So, whether you’re lounging around the house or forging out into the cold, nothing beats long underwear in the winter months when it comes to warmth, comfort, and style.

We’ve put together a list of the best long underwear bottoms to keep you toasty and comfortable this winter season.

Check it out, grab a few pairs, and enjoy those chilly months both outdoors and in.

Note: Featured products are independently selected and reviewed by The Underwear Review. If you purchase through our links, we may earn commission.

1. Tommy John SleekHeat Long Johns

The Tommy John SleekHeat Long Johns feature a silky soft premium fabric that’s featherlight and non-pilling. These long johns have a streamlined fit that perfectly hugs your body while providing a non-restrictive full range of motion.

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Tommy John’s SleekHeat Long Johns feature signature smart fabric that keeps you warm outdoors and prevents overheating while indoors. These long johns also utilize smart stretch technology to prevent moisture build-up.

2. David Archy Ultra Soft Thermal Long Johns

The David Archy Ultra Soft Thermal Long Johns feature an incredibly soft fleece fabric in a slim fit that lays smoothly against your skin. These thermal long johns are double-sided for superior body heat retention and comfort.

Shop at David Archy: David Archy Ultra Soft Thermal Long Johns

David Archy’s Ultra Soft Thermal Long Johns feature a double-layer knee panel for improved durability and warmth, as well as a functional fly for convenient access.

3. Mack Weldon Tech Merino Jersey Long Johns

The Mack Weldon Tech Merino Jersey Long Johns feature a luxuriously soft modal fabric that’s ultra-lightweight and provides optimal stretch.

Shop at Mack Weldon: Mack Weldon Tech Merino Jersey Long Johns

Mack Weldon’s Tech Merino Jersey Long Johns utilize the technical performance properties of merino wool that’s naturally moisture-wicking and antimicrobial.

4. Mack Weldon WARMKNIT Long Underwear

The Mack Weldon WARMKNIT Long Underwear features signature micro-waffle knit fabric with insulating Thermolite technology for a lightweight warmth.

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Mack Weldon’s WARMKNIT Long Underwear has a classic long underwear style in a comfortable fit with stay-put ankle cuffs and a no-roll waistband.

5. Smartwool Thermal Merino Base Layer Bottoms

The Smartwool Thermal Merino Base Layer Bottoms feature 100% Merino wool fabric in a slim functional fit. These base layer bottoms utilize an interlock knit for enhanced comfort, breathability, and thermoregulation.

Shop at Smartwool: Smart Wool Thermal Merino Base Layer Bottoms

Smartwool’s Thermal Merino Base Layer Bottoms keep you warm during outdoor activity with a heavier weight fabric while minimizing chafing with a flatlock seam construction. These base layer bottoms have a comfortable merino-covered waistband and a traditional fly design.

6. NATIVE TO WEAR Base Layer Bottoms

The NATIVE TO WEAR Base Layer Bottoms feature an incredibly soft merino wool that contains pure silver to evenly spread body heat for ideal temperature regulation in both cold and hot weather conditions. Available in 3 color options.

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NATIVE TO WEAR’s Base Layer Bottoms incorporate Lycra stretch into the fabric for a stretchy second skin fit that provides maximum comfort and freedom of movement. These base layer bottoms are breathable, sweat-wicking, and antibacterial.

7. 2(X)IST Essential Cotton Long Johns

The 2(X)IST’s Essential Cotton Long Johns feature a comfortable and breathable combed cotton fabric (100% cotton) that’s available in classic colors and plaid. These long johns are a great layering option for both outdoor and indoor wear.

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2(X)IST’s Essential Cotton Long Johns have a classic functional fly, cuffs, and a waistband that sits comfortably at the hip.

8. 2(X)IST Warm-Knit Merino Long Johns

The 2(X)IST Warm-Knit Merino Long Johns feature a comfy and toasty merino wool fabric with body regulating technology so that you stay warm without overheating.

Shop at 2(X)IST: 2(X)IST Warm-Knit Merino Long Johns

2(X)IST’s Warm-Knit Merino Long Johns utilize a classic functional fly design with comfortable ribbed cuffs and a waistband that sits at the hip. These long johns have breathable fabric with added stretch for a comfortable full range of motion.

9. SAXX Roast Master Mid-Weight Tights

The SAXX Roast Master Mid-Weight Tights feature a textured knit fabric that provides thermal comfort and warmth. These base layer tights have a form-fitting slim fit, easy access fly, and sweat and odor fighting technology.

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SAXX’s Roast Master Mid-Weight Tights utilize a signature BallPark Pouch and Flat Out Seams for extended wear comfort. These base layer tights are also available in extra warm Heavyweight.

10. Columbia Omni-Heat Infinity Baselayer Tights

The Columbia Omni-Heat Infinity Baselayer Tights feature a signature Omni-Heat thermal-reflective lining for advanced body heat retention without fabric bulk. These baselayer tights utilize comfort stretch fabric for a snug fit that’s non-restrictive.

Shop at Columbia: Columbia Omni-Heat Infinity Baselayer Tights

Columbia’s Omni-Heat Infinity Baselayer Tights feature signature sweat-wicking Omni-Wick technology that moves sweat away from your skin and neutralizes odor for a long-lasting dry and fresh feel.

11. Male Basics Pima Long Johns

The Male Basics Pima Long Johns feature an incredibly soft Pima cotton with a touch of lycra stretch for an ideal fit. These long johns have a snug and comfortable fit that’s great for wearing alone or layering up.

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Male Basics’ Pima Long Johns have a full leg length that sits at the ankle with ribbed cuffs to prevent riding up. These long johns have a stay-put elastic waistband and are available in four classic color options.

12. Male Basics Microfiber Long Johns

The Male Basics Microfiber Long Johns feature a soft and stretchy microfiber fabric that’s great for warmth during activity and everyday wear. These long johns utilize moisture-wicking technology to keep you dry and fresh all day.

Shop at Male Basics: Male Basics Microfiber Long Johns

Male Basics’ Microfiber Long Johns have a breathable slim fit with 4-way stretch for a chafe-free full range of motion.

13. Ergowear MAX XV Long Johns

The Ergowear MAX XV Long Johns feature an incredibly soft stretch fabric that layers great for outdoor activity and provides comfortable warmth for indoor relaxing.

Available on Amazon: Ergowear MAX XV Long Johns

Ergowear’s MAX XV Long Johns have a sleek and flattering fit with a wide elastic waistband for stay-put coverage and ankle length legs.

14. Thermajohn Thermal Long Johns

The Thermajohn Thermal Long Johns feature an extra soft fleece lining for extended comfort and heat retention. These thermal long johns utilize 4-way stretch fabric for a no-chafe fit that’s also breathable and moisture-wicking.

Available on Amazon: Thermajohn Thermal Long Johns

Thermajohn’s Thermal Long Johns work great for layering up to fight cold weather or to wear on their own as a comfortable pajama option. Available in multiple colors.

How Should Long Underwear Fit?

If you’re looking for additional warmth in the colder winter months, long underwear is the most popular go-to option.

A full set of long underwear consists of both a top and bottom, though either can be worn separately on their own to match personal preference.

Additionally, tops and bottoms can typically be purchased separately.

Both pieces are designed to be worn as base layers, which means they’re the first layers you put on and worn right against your skin.

Long underwear pieces are then typically layered with top/outer layers.

For this reason, your long underwear should have a snug, body-contouring fit.

This not only allows for additional layers to wear nicely over the top but it’s also what helps with body heat retention, keeping you warmer for longer.

When sizing your long underwear, look for a snug and comfortable fit.

It should fit close to your body but should not restrictive your movement or cause any discomfort.

Long underwear is typically worn out of sight, so you may want to keep this in mind when determining the length of your sleeves or legs.

However, this isn’t always a priority, especially when wearing long underwear for outdoor activities.

Additionally, the leg cuffs of long underwear are typically tucked into your socks.

This allows for a more polished appearance when wearing them indoors and helps to keep out the cold and snow when outdoors.

Are You Supposed to Wear Underwear Under Long Underwear?

Whether you’re a first timer or just never felt certain as to how the garment was intended to be worn, wondering whether you’re supposed to wear a pair of regular underwear under your long underwear is a common question.

In certain ways, you’ll notice how long underwear mimics a regular pair of underwear.

For example, the waistband is identical, some pairs have a functional fly, and often the fit around the groin, glutes, and thighs is similar.

However, there are also a few differing characteristics that might make you question how long underwear is supposed to be worn.

In particular, it’s the length of long underwear, which is similar to a pair of pants, that tends to raise this question the most.

So, are you supposed to wear underwear beneath your long underwear?

The answer is right there in the name. Long underwear is technically underwear, so, no, you don’t need to wear underwear with your long underwear.

Long underwear is designed to provide all the qualities and benefits of your usual underwear.

However, it’s also a matter of personal preference.

Some people may prefer wearing a pair of underwear beneath their long underwear, whether for additional support, comfort, etc.

This is perfectly fine, as well.

Keep in mind, though, that even though you’re likely trying to ward of cold weather when wearing long underwear, the more layers you wear (including underwear), the less breathability you’ll have.

So, depending on your outdoor activity, you’ll want to keep this in mind. High-intensity activities may lead to overheating if you’re wearing too many layers.

If you're looking for a full set of long underwear for this winter, check out our picks for the Most Comfortable Long Underwear Sets.

And if you’re all about comfort when it comes to your shirts, socks, and underwear be sure to check out the rest of our Most Comfortable Series.