Boxer briefs are a type of men's underwear. They are long, like boxer shorts, but tight, like briefs (often nicknamed "tighty whities"), a compromise between the two main types of male underwear in the United States.

Boxer briefs were first sold around 1990. They haven't achieved the popularity of boxers shorts or briefs yet, but they are rising in popularity, in due part because of their proximity to both briefs and boxer shorts. They are commonly used in athletics instead of a jockstrap, but are common for everyday usage as well.

The boxer brief design provides form-fitting coverage for the midsection from the waist to the thighs and are worn on the waist. Boxer brief designs can have either an access flap, button front,pouch, and sometimes no fly at all. The trunk is a type of boxer-brief that is slightly shorter.