Boxer shorts (also known as loose boxers or as simply boxers) are a type of undergarment typically worn by men. The term has been used in English since 1944 for all-around-elastic shorts, so named after the shorts worn by boxers, for whom unhindered leg movement ("footwork") is very important.

Reasons for a preference for boxers can be attributed to their variety of styles and design as well as the way boxers look on the wearer. Unlike traditional briefs or the more modern boxer briefs, boxers allow for more freedom in the selection of a fabric type and print design.

In 1925, Jacob Golomb, founder of Everlast, designed elastic-waist trunks to replace the leather-belted trunks then worn by boxers. These trunks, now known as "boxer trunks", immediately became famous, but were later eclipsed by the popular Jockey-style briefs beginning in the late 1930s. Around 1947, boxer shorts started to gain in popularity again.^{[citation needed]} The two styles, briefs and boxer shorts, had varying ratios of sales for the following forty years, with strong regional and generational preferences.