The union suit, also known as the onesie with the flap in the back (or waffle knit thermal), is perfect for winter wear. Designed to keep you cozy, it provides a base layer for your outer clothes so you can stay nice and toasty.
However, finding a union suit that fits your body to the tee isn’t always easy. A one size fits all garment is hard to find.
Some union suits may fit your torso but not your arms or legs. Then others may accommodate your height but feel too tight around the ankles or wrists.
An ill-fitting union suit makes it hard to feel comfortable. Another challenge to feeling well supported is the chafing factor.
To enjoy your union suit, you need to make sure it’s designed to provide a friction-free experience.
Additionally, you want to make sure that the quality of the suit is good so that you’ll also be able to stay warm while wearing it.
Thankfully, there are plenty of chafe-free union suits that will keep you warm and fit your body well. This guide lists the best union suits to fit your lifestyle and preference.
Top 10 Best Union Suits
Duofold
Carhartt
Hanes
Pro: Tagless.
Con: Torso a bit short.
Breathable fabric: Hotouch’s union suit is designed to respond to temperature changes in your environment. You can expect to stay comfortable all day long.
This has buttons all the way to the crotch area making it easy to get in and out of this number. Made using a soft blend of 65% polyester and 30% cotton, this bad boy will let your skin breathe while still keeping you nice and toasty.
This union suit is super comfy, luxurious, and very well made. It’s roomy. Plus, it has the right length, thickness, and softness to keep you warm in winter months.
The opening in the back is great. You only have one button to deal with and it's an overlapping slit rather than a flap that can get caught under you when it opens.
This will fit men with athletic builds really well. The higher armholes and lower trouser rise are ideal for strong physiques.
The close fit along the torso and connections to extremities allow for better movement. The downside is that it feels tight in the crotch. Prevent this from being an issue by going up a size.
Pro: 60% organic cotton.
Con: Need to size up.
Flat no rub seams: This union suit feels smooth against the skin and prevents chafing. The cross-stitching design has a sporty look. It’s rather lightweight and has a tight fit.
Also, it holds up well after being washed in hot water. It won’t shrink and the color won’t bleed. The waffle knit adds a nice look and texture.
The fit is perfect. Both the sleeve and pant lengths are spot on.
The downside is that the flap in the back is a single button closure which can be awkward when going to the bathroom. Prevent issues with it by relieving yourself as soon as nature calls instead of holding it in.
Pro: Warm waffle knit.
Con: Bigger around the stomach and rear area.
Durable: Noble Mount’s union suit is made with a blend of 60% cotton and 40% polyester. Cotton brings comfort while polyester brings durability to the table.
This union suit provides a superior fit and feel. The lightly brushed fabric allows it to retain body heat better than non-brushed fabrics during cold temperatures.
Waffle knits are great at preventing cold airflow so you can feel warm when the weather turns nippy. The fabric is thick and holds up well which speaks to the high quality of the product.
The seams are well done and don’t leave stray strings hanging off the suit. There are enough buttons in the front for good closure and the back flap is easy to use when you need to utilize the facilities.
However, it feels tight around the ankles and calves. Stop this from being a problem by wearing it around the house a couple of nights to stretch it out a bit before wearing it under your winter gear.
Pro: Comfortable.
Con: Waist and crotch are a bit baggy.
Great fit: Zexxxy’s union suit is incredibly comfortable and fits as it should. It is high quality and the material is quite nice.
This suit is warm enough to help keep you toasty while deer hunting. Yet, it isn’t too thick or bulky so you’ll still be able to move around in it.
A full-button placket and crew neckline offers you total body comfort from wrist to ankle regardless of the conditions outside. Soft, comfy, and lightweight, this union suit will make a wonderful addition to your cold-weather gear.
Another perk is that you can wash it multiple times and the fabric will still hold up nicely. The downside is that the way the seams come together between the legs can make you feel like you’re wearing a diaper.
Keep this from being a problem by wearing boxer briefs to keep them from rubbing your thighs.
Pro: Shrinkage controlled.
Con: Small trap door.
X-temp technology: Hanes made a soft union suit that adapts to your body’s temperature. The waffle thermal knit fabric has flat no rub seams and comfortable rib-knit cuffs.
This suit is super comfortable. It’s perfect for working outside in the elements or just lounging in the comfort of your home watching TV.
The fabric is lightweight and provides excellent warmth. It’s also good at wicking away moisture and will help you stay dry while working or playing.
The downside is that it may feel itchy at first. However, this doesn’t have to be a dealbreaker. Wash it in fabric softener.
Pro: 100% cotton.
Con: No snap for the crotch.
Ribbed side panels: This super-soft union suit is fitted for base layer comfort. The fabric is lightweight and has a little stretch.
Comfy and cute to boot, this suit has enough space in the front to maintain modesty. Plus, it will do an excellent job of keeping you warm. The fit is true to size.
There’s no bunching in the arms and legs. Plus, the torso has just the right amount of snugness. On the other hand, this has a hole under your crotch that’s designed to let your Johnson slip through for bathroom trips.
This creates an unpleasant draft. Stop this from being a problem by wearing underwear underneath if needed.
Pro: Front vertical seat flap.
Con: Only one color.
No bunching: Indera’s union suit is made of soft cotton that feels amazing. The construction is sturdy. The buttons don’t come off easily.
Moreover, the sleeves and legs don't bunch or slide up your limbs while you sleep. You can wear this for months and it will still have a snug fit after many washes.
The fabric is heavy enough to keep you warm when the temperature dips in your house. Plus, the breathable cotton makes it easy to wear this suit in the summer when the temps are above 75 degrees at home.
The fit is excellent and the back flap is adequate as well as appropriate. On the other hand, this undy will shrink if washed in hot water and placed in the dryer.
Prevent this from happening by washing it in cold water and letting it air dry.
Pro: Two-layer thermal for warmth.
Con: Shrinks a lot.
All-natural blend: Duofold’s union suit is made of a blend of cotton and merino wool that helps keep you warm. The double-layer design is much better at retaining heat than the single-thickness union suits.
Plus, it fits perfectly. It’s neither too tight nor too small. The sleeves aren't too long or too short, but just right.
Another bonus is that it goes under regular clothes and tight jeans without feeling awkward. This union suit is very comfortable.
When you wear this as a base layer, it keeps you warm. The insulation is excellent. However, if you don’t layer properly, your socks will fall down.
Solve this issue by remembering that your socks go on under not over your union suit. Keep your socks on your legs.
Pro: Rugged flex technology.
Con: Seams may be scratchy.
Tagless: Carhartt’s union suit makes excellent use of strategic seam placement for maximum comfort and reduced chafing. Smooth flatlock seams enhance comfort.
A well-designed waffle knit traps heat. The rugged flex technology allows for ease of movement making this is a very comfy number to wear.
The ribbed cuffs double over nicely at the wrist and ankle. The stitching is well done and the buttons are secure.
However, the generous opening in the back can be bothersome. Remedy this issue by sewing it up on the outside and the inside.
Pro: Ribbed wrist & ankle cuffs.
Con: Very thin material.
Quality material: North 15’s union suit provides a wonderful fit. It goes nicely under your clothes and feels comfortable. The fabric is soft and stretchy. Plus, it isn’t too thick.
Yet, it is good at keeping you warm. It’s similar to the waffle weave. The cut of the suit is good. There’s a slit in the back that’s full size and makes bathroom trips easier.
On the flip side, this has a tendency to be a bit big out of the package. Fix this by washing it in hot water twice. Also, put it in a dryer twice.
Best Union Suits Buying Guide
The best union suits will have a great fit and provide warmth. They won’t chafe, bunch, or make you feel uncomfortable.
A great suit will perform equally well for you whether you’re doing construction work, lounging at the house, or hitting the slopes.
Here are the key features to look for when choosing the best union suits.
Temperature Control Union Suits
The beauty of a good union suit is that it can help your body retain heat during cold months. No one likes to face the elements unprepared.
Opt for a warm waffle knit that’s combined with brushed fabric for maximum heat retention. You’ll be able to keep cold airflow from putting a damper on your outdoor activities when the weather turns chilly.
- FABRIC: Noble Mount Union Suit is made from Cotton rich blend of 60% Cotton and 40% Polyester. Cotton...
- STYLING: Our union suit men love features sturdy rib cuffs that provide stretch. Button Placket all the...
- WARMTH: Our thermal union suit/adult onesies for men are made from lightly brushed fabric. This lends it...
Anti-Chafing Union Suits
Chafing is never fun. Avoid that uncomfortable feeling like the plague. Choose a union suit with flat no rub seams to prevent chafing.
It will provide for a much smoother feeling experience. Your thighs will thank you.
Best Fitting Union Suits
You want the suit to also feel good under your clothes. It should be snug but also roomy enough to allow for movement.
The sleeve and pant lengths should be spot on. Opt for a close fit along the torso with connections to your extremities.
Undywear.com may receive a small percentage of the purchase price for items bought through our links from Amazon.com and other sites.
