In theatre or performance arts, the stage (sometimes referred to as the deck in stagecraft) is a designated space for the performance productions. The stage serves as a space for actors or performers and a focal point (the screen in cinema theaters) for the members of the audience. As an architectural feature, the stage may consist of a platform (often raised) or series of platforms. In some cases, these may be temporary or adjustable but in theaters and other buildings devoted to such productions, the stage is often a permanent feature.

There are several types of stages that vary as to the usage and the relation of the audience to them. The most common form found in the West is the proscenium stage. In this type, the audience is located on one side of the stage with the remaining sides hidden and used by the performers and technicians. Thrust stages may be similar to proscenium stages but with a platform or performance area that extends into the audience space so that the audience is located on three sides. In theatre in the round, the audience is located on all four sides of the stage. The fourth type of stage incorporates created and found stages which may be constructed specifically for a performance or may involve a space that is adapted as a stage.