A curtain raiser is a short performance or performer that introduces a show or event before the main attraction. It is usually shorter than the main attraction, though this is not always the case. The term comes from the action of raising the curtain on a stage.

During the late Victorian and Edwardian eras, it was common to have long theatre performances. These often included full-length plays along with shorter companion pieces. Each full-length work was typically paired with one or two short companion pieces. If the short piece was performed first, it was called a curtain raiser. If it was performed after the full-length piece, it was called an afterpiece.

W. J. MacQueen-Pope noted that curtain raisers were an important part of theatre traditions.

In Australian rules football, it is common to have a youth game or a lower-division game as a curtain raiser before the main game.