A leather jacket is a type of clothing, a jacket made of leather. The jacket has usually a brown, dark grey or black color. Leather jackets can be styled in a variety of ways, and different versions have been associated with different subcultures. For instance, the leather jacket has often been associated with bikers, military aviators, rock stars, punks, metalheads, and police, who have worn versions designed for protective purposes and occasionally for their potentially intimidating appearance.

In the 20th century the leather jacket achieved iconic status, in major part through film. Examples include Marlon Brando's Johnny Strabler character in The Wild One (1953), Honor Blackman as Cathy Gale in The Avengers, and Michael Pare in Eddie and the Cruisers (1983). As such, these all served to popularize leather jackets in American and British youth from the "greaser" subculture in the 1950s and early 1960s. A later depiction of this style of jacket and time was "The Fonz" in the television series "Happy Days" which was produced in the 1970s and 1980s but depicted life in the 1950s and 1960s. The Fonz's leather jacket is now housed in the Smithsonian Institution, and the Grease movie duo has also since popularized leather jackets with their T-Birds male clique. Back then a leather jacket would have cost between $7 to $20 which was expensive considering the time.

The leather jackets worn by aviators and members of the military were brown and frequently called "Bomber jackets" as seen on numerous stars in the 1940s and 1950s such as Jimmy Stewart in the 1957 film, Night Passage. The brown leather jacket has been a de rigueur part of the wardrobe of a Hollywood adventurer, from Gary Cooper in For Whom the Bell Tolls to Harrison Ford in the Indiana Jones film series. While the black leather jacket fad ended in the early 1960s, bomber jackets, often with sheepskin collars, have remained popular. They can be seen in the 1986 film, Top Gun.

There is a substantial difference between leather jackets made for fashionable purposes and those worn for protection (in activities such as motorcycle riding). Leather jackets designed for protective use are safety equipment and are heavier, thicker, and often equipped with armor, thus becoming a very practical item of clothing regardless of the symbolism invested in them by popular culture. A leather jacket primarily designed for fashion purposes is not likely to be of much use in a motorcycle accident.

Leather jackets were also popular with the Russian Bolsheviks and were nearly a uniform for the Commissars during the Russian Civil War and later for the members of the Cheka. This practice is said to have been initiated by Yakov Sverdlov.