Meet Your New Favorite Undershirt
Slip one on and feel the difference — no bunching, no bulk, just sleek, all-day comfort.
- Stays tucked all day
- Invisible under any shirt
- Tailored, sleek fit
- Ultra-soft & breathable
365-Day Feel Good Guarantee
Tried so many undershirts that didn’t cut it. UnderFit nailed the fit, comfort, and quality. I’m never switching back.
Dr. Jeff M.
Verified Buyer
Disappears under unbuttoned shirts for a clean, polished look.
A crisp, classic layer that works with every shirt.
Smooth and modern. Designed to layer under shirts.
Fades under dark clothing for a seamless appearance.
Blends under light shirts for a smooth, invisible foundation.
A staple layer made for dress shirts, sweaters, and beyond.
Neutral and modern. Built to anchor any outfit with ease.
Simple and sharp. A versatile pick for every wardrobe.
“Our #1 recommendation”
UnderFit combines comfort and performance for the ultimate undershirt experience.
Connor L.
Black Lapel Suits
Your Undershirt Should Work as Hard as You Do
Most undershirts fail at their one job — staying comfortable and out of sight. They bunch up, billow, and come untucked when you need them to stay put.
We fixed that.
- Smoother, slimmer look – No loose fabric, no excess bulk.
- Odor-resistant & moisture-wicking – Stay fresh from morning to night.
- All-season comfort – Cool in summer, warm in winter.
- Eco-friendly & sustainable – 1/20th the environmental impact of cotton.
Once You Try One, You’ll Never Go Back
Don’t just take our word for it. Read a few reviews — and if it’s not a perfect fit, return it within 365 days. No hassle.
I tried a wide range of brands before finding UnderFit. Now my drawer’s full of crew and v-necks I wear year-round. Comfortable in NYC’s freezing winters or sweltering summers. I won’t wear anything else.
James B.C.
Verified Buyer
I wear deep V undershirts most days with a few buttons undone. The beige is way less visible than my old white Tommy John. Size large fits perfectly.
Andy D.
Verified Buyer
I used to wear Thompson Tee, but UnderFit’s darker beige hides better under a white dress shirt. Wore it on my wedding day — looked great, felt great, and gave me the confidence to enjoy every moment.
Tristan Z.
Verified Buyer
I’ve tried performance undershirts for 13 years and wasted plenty on ones I didn’t like. UnderFit is the first that truly works. Stays tucked, sleeves stay hidden, handles Arizona heat, and still looks new after a year of weekly wear. Worth it.
Ryan W.
Verified Buyer
Best undershirts I’ve ever tried (and I’ve tried a bunch). So comfortable I forget they’re there. And they never come untucked. And the sleeves are short enough they don’t peak out of my t-shirts.
Tim C.
Verified Buyer
I’ve been wearing these for years. They fit great. Comfortable. They don’t come untucked. They protect your shirts. They last a long time. Customer service is excellent too.
Aron Y.
Verified Buyer
I bought my first V-neck in 2016 and have ordered several more since. They’re incredibly comfortable, hold up to daily wear, and the fabric is perfect for Florida heat. Light but not flimsy. Fantastic product I wear daily.
James K.
Verified Buyer
Hands down, these are the best undershirts I have found. They are soft, comfortable, and most importantly they don’t show with my dress shirts.
Christopher S.
Verified Buyer
I love these shirts, I have 3 of them. They feel great, fit snug, stay hidden, and I wear them anytime I want to protect a shirt from deodorant or sweat stains. Essential if you want to keep your nice shirts looking new.
Aaron F.
Verified Buyer
A Perfect Fit That Keeps You Cool, Crisp & Confident
Your shirt should fit like it was made for you. With UnderFit, you’ll always look sharp — whether at the office, out for the night, or just lounging at home.
- Feels like a second skin – So light, you’ll forget you’re wearing it.
- No pilling, no fading – Stays smooth after countless washes.
- Wicks 50% more moisture – Keeps you cool and dry all day.
Ridiculously Soft.
Sustainably Made.
Most brands use viscose or basic cotton — both waste tons of water and rely on harmful chemicals.
Our TENCEL™ fabric is next-level soft and eco-friendly.
Better for you. Better for the planet.
- All-day breathability – Light, flexible, never sticky.
- Wicks moisture fast – Keeps you dry and comfortable.
- Sustainable choice – Less impact than traditional cotton.
