A projection display device includes: a light modulation unit that spatially modulates, in accordance with image data that is input, light emitted by a light source; a housing that accommodates the light modulation unit; a projection optical system that is accommodated in the housing and projects the light that has been spatially modulated onto a projection surface of a vehicle through an opening portion of the housing; and a cover that closes the opening portion, the cover has a shape whose longitudinal direction is a direction extending from a driver's seat of the vehicle toward a passenger seat of the vehicle, and a front surface of the cover is closer to the projection surface than a reference plane and has a shape as defined herein.