Men's Cotton Boxers short

The Mariner Underwear men's cotton boxers collection is built on pure combed cotton poplin, a woven fabric with a fine, tight weave rather than a stretch jersey knit. Every pair uses a loose, classic cut through the leg and seat, finished with an American-style back cut in multiple panels for extra room to move. Shop single pairs or 2-packs, sizes S to XXL

What's in the Collection

Every style in this range starts with the same base cloth: combed cotton, woven into poplin rather than knitted into jersey. The tight weave gives it structure and a crisp handle. It's breathable and holds up well through a full day of wear.

Beyond the base cloth, the range runs from plain solid colours to printed designs, and includes a handful of pairs with extra detailing: an inner support lining in some, and a fully open, button-front waist in one style. Whatever the print or the extra feature, the loose cut stays consistent across the range.

A Loose, Classic Fit

This is the main difference from Mariner Underwear's other boxer styles. Rather than a close, stretch fit, these boxers sit away from the leg, cut on a relaxed pattern with an American-style back in multiple panels for more room through the seat and less pulling when you move.

A man after a closer fit can look at the men's boxer shorts range instead, a brief-cut cotton stretch jersey with a shorter leg. This woven collection is the wider, more relaxed option of the two.

Support Lining and an Open-Front Style

A few pairs add an inner lining in soft cotton jersey, stitched to the front for extra hold with no added compression. The lining sits close without adding bulk, so the boxer keeps its relaxed drape at the leg. These are listed as slipped styles.

One design skips the elastic waistband altogether for an open, button-front closure: two buttons at the front, and the same relaxed leg as the rest of the range. Some men simply prefer the traditional build.

Colours and Patterns

Solid options include navy, blue, plum, bordeaux, white, ecru and grey. Printed pairs cover stripes, checks and tartan, small florals, polka dots and geometric patterns, often mixed within a single 2-pack so you get one plain pair alongside one patterned pair. Buying a couple of packs at once is a straightforward way to build up a drawer of everyday cotton boxers without picking every colour one at a time.

Packs and Sizes

You can buy these as a single pair or as a 2-pack, usually a solid shade paired with a coordinating check or print. Sizing runs S to XXL on Mariner Underwear's usual scale, internal codes 2 to 6. Because the cut sits looser than the brand's fitted lines, check the size guide on each product page if you're between two sizes. Stock on individual colours and prints can shift week to week, so it's worth checking availability before you build a full order around one specific design.

Care

Machine wash at 30 degrees. The cotton poplin can be tumble-dried on a low setting, though air-drying keeps it looking sharper for longer and is kinder to the weave over time. Skip the fabric softener. It flattens woven cotton and dulls the crisp finish that's the whole point of choosing poplin. As with most cotton pieces, wash a new pair on its own for the first cycle or two, since fresh cotton can release a small amount of dye.

Cotton Boxers, Boxer Shorts or Trunks: Which to Pick

This collection uses a woven poplin and a loose, classic cut through the leg and seat. It suits a man who wants room to move and doesn't want a fitted band against the skin all day.

For something closer, the men's boxer shorts range is a cotton jersey knit with a shorter, brief-cut leg. The men's trunks underwear range sits between the two, a square-cut style in an organic cotton stretch fabric finishing at mid-thigh.

Go loose and woven if stretch fabric ever feels tight at the waist, or if the classic boxer shape is simply what you're used to. Go boxer shorts or trunks for a fitted style that stays put through sport or under close-cut trousers.

Frequently Asked Questions

What are men's cotton boxers made of?

They're cut from pure combed cotton poplin, a woven fabric rather than a stretch jersey knit. The weave gives the fabric structure and a crisp feel, and every style is machine washable at 30 degrees.

Are these cotton boxers loose or fitted?

Loose. The cut is a classic, relaxed boxer shape with an American back cut in multiple panels, built for room through the seat rather than a close fit. For a fitted style, see the men's boxer shorts collection instead.

What sizes do men's cotton boxers come in?

Sizes run from S to XXL, using Mariner Underwear's internal codes 2 to 6. The loose cut gives more room than the brand's fitted styles, so check the size guide on each product page if you're between sizes.

Do men's cotton boxers have a button fly?

One style uses an open, button-front waistband with two buttons instead of full elastic. Most other styles in the collection have a standard elasticated waistband.

How do I wash cotton boxers?

Machine wash at 30 degrees. Tumble dry on low if needed, though air-drying keeps the poplin looking sharper for longer. Skip the fabric softener, it flattens the weave.

What's the difference between cotton boxers and boxer shorts?

Cotton boxers here are woven poplin in a loose, classic cut. Boxer shorts are a stretch cotton jersey in a closer, brief-cut style with a shorter leg. Both are pure cotton based, the difference is the weave and the fit.

Can I buy cotton boxers in a pack?

Yes. Most styles come as a 2-pack, usually a solid colour paired with a check or print. A few styles are sold individually.