Greasers were a working-class youth subculture that originated in the 1950s among teenagers in northeastern and southern United States. Rock-and-roll music was a major part of the culture, and styles were influenced by singers, like Eddie Cochran, Gene Vincent, Johnny Burnette, Vince Taylor and Ritchie Valens, but the two main figures of the look were Marlon Brando and James Dean.

In the 1950s and 1960s , these youths were also known as "hoods". This may be due to the fact that the style was more popular in poor neighborhoods that had higher crime rates than upper-class neighborhoods.

Greasers grew out of post–World War II social and economic conditions, particularly among working-class and lower-income youths in urban neighborhoods. Many came from Italian American, Mexican American, and other Latino backgrounds, and the subculture expressed frustration with a conformist, middle-class 1950s society that they felt excluded them.

The name "greaser" came from the greased-back hairstyles these people wore (which involved combing back hair using hair wax, hair gel, creams, tonics or pomade), though it also originally functioned as a slur, tied to earlier racist usage against Mexican laborers in 19th‑century California. By the 1950s it became associated with urban “hoods” or “toughs,” and middle-class Americans often viewed greasers as threatening or delinquent even as they were also romanticized as exciting outsiders.

Women also became a part of greaser culture. Like men, they joined motorcycle gangs and wore jackets displaying their group's or gang's name. Latina women involved in gangs typically did not fight side-by-side with male gangs, but they did fight rival female gangs in the 1950s. Women were often depicted as the property of male motorcycle gang members.

Although greasers were largely a North American youth phenomenon, there were similar subcultures that sprouted up in the United Kingdom, Australia, Italy, Japan, France, Sweden, Germany, New Zealand and South Africa, due to the influence of American culture and media. In France, they are called "blousons noirs". The 1960s British Rockers, also known as a "ton-up boy", took inspiration from the Greaser image. Unlike British rockers, who were exclusively bikers, North American greasers were known more for their love of hot rod cars, kustoms and vans, not necessarily motorcycles. Both subcultures are known for being fans of 1950s Doo Wop, Rock and Roll, and Rockabilly music.

By the mid‑1960s the original greaser scene faded as youth culture shifted toward other movements, though related styles persisted in some working-class communities and biker cultures. Greasers reappeared in later decades as part of a revival of 1950s popular culture. One of the first manifestations of this revival was a 1971 American 7 Up television commercial that featured a 1950s greaser saying, "Hey remember me? I'm the teen angel." The music act Sha Na Na also played a major role in the revival.

Clothing usually worn by greasers included:

Common accessories included:

Common footwear included:

In England, the greasers are called "Teddy Boys" and they wear drape jackets, creepers and ducktail hairstyles. Typical hairstyles included the pompadour, the Duck's ass, S-Curls, Finger Waves, Afros with parts or shaped like pompadours, and the more combed-back "Folsom" style. These hairstyles were held in place with pomade like suavecito and layrite, wax, or hair creams such as brylcreem. Another variant of greasers were "Ton-Up Boys", who wore pompadours, Leather Jackets, blue jeans or leather pants, and jack boots. They rode motorcycles modified to go 100 Miles An Hour or more, and we're known as "Rockers."

The leather jacket, as popularized by pilots during World War II, became an icon of greaser culture. Compared with the previous decades, the 1950s were considered dull and the youths craved a new sense of adventure. The leather jacket marked greaser youths as daring and adventurous young men, like the pilot heroes of the recent war.