# Image projector, a device that projects an image on a surface * Video projector, a device that projects a video signal from computer, home theater system etc. * Movie projector, a device that projects moving pictures from a filmstrip * Slide projector, a device that projects a still image with a transparent base * Overhead projector, a device that projects a transparent image * Opaque projector, a predecessor to the overhead projector * Magic lantern (projector), a historic projection device * Camera obscura, the historic ancestor to projection devices * Enlarger, a device used to produce photographic prints from negatives # Ceiling projector, a device used to measure the height of clouds # Projection (linear algebra), a linear transformation of a vector space # Projector (album), an album by Dark Tranquillity