A swim brief or racing brief is any briefs-style male swimsuit such as those worn in competitive swimming, diving and water polo. The popularity of the Australian Speedo brand racing brief has led to the use of its name in many countries around the world to refer to any racing brief, regardless of the maker. Occasionally, the speedo genericized trademark is applied to square cut swimsuits, but in general the generic term is used in reference to swimming briefs. Swim briefs are also referred to as competition briefs, swimming trunks, bathers, togs, racer bathers, posing briefs, racing briefs, and colloquially in Australia, New Zealand, and the United Kingdom as budgie smugglers.

Briefs are a type of short, form-fitting underwear and swimwear, as opposed to styles where material extends down the thighs. Briefs have various different styles, usually with a waistband attached to fabric that runs along the pelvis to the crotch and buttocks, and are worn by both men and women. Swim briefs are a variation used as swimwear.