Old School is a slang term referring to old ways of thinking or acting, and to old objects in general within the context of popular culture of the 1970s, 1980s and 1990s (while it refers to vinyl, it is not generally used to describe wax cylinders ). It generally does not have a negative connotation (cf. obsolete or out dated). Common usages include Old school Hip hop, referring to the rap music of anywhere from the late 1970s to the early 1990s. Hip hop historians consider the late 70s to the early 80s to be old school, then the late 80s to 90s as Golden Age, but the mainstream often refers to the late 80s, early 90s period as Old School. The border for old school for computer games is often drawn at 3D and 32-bit games.

In the world of rock music, Old School usually refers to the period between the early 1970s, when hard rock and heavy metal emerged, and the early 1990s, just before the advent of grunge. This period is a common format for classic rock/AOR radio stations.

Old School is often interchangeably used with the word nostalgia but practitioners of semantics often define old school as simply of an earlier period but not neccesarily inferior or hopelessly dated. Nostalgia, on the other hand is often given the negative connotation, for example as a sentimental attachment to dated works many of which are now considered embarrasingly corny or cheesy in their execution. This definition is often associated with cartoons and other children's shows, especially after one reaches adulthood. As a result, many apply the term old school as if one would say "They just don't make 'em like this anymore."

Old School is also a 2003 novel by Tobias Wolff.

Old School is also a motion picture produced by DreamWorks SKG starring Will Ferrell, Luke Wilson, and Vince Vaughn.