Off-Broadway theater refers to stage plays or musical theater performed in New York City, in venues of a smaller size than Broadway theaters. Generally Off-Broadway shows are less expensive, less publicized, less well-known and feature less-famous performers. The smaller scale also often allows more experimental, challenging work to be presented.

The classification of theaters is governed by language in Actor's Equity contracts, rather than by whether the theater has a Broadway address.

It is not unknown for successful Off-Broadway shows to later have a Broadway run - for instance, the musical Rent was initially shown Off-Broadway.