A projection device includes a correction unit that corrects a trapezoidal distortion of a projection image projected onto a projection medium in accordance with a projection angle derived by a projection angle deriving unit, and the correction unit sets a correction amount for the trapezoidal distortion of a case where the derived projection angle is changed within a range larger than a first predetermined angle determined based on the projection direction toward a boundary between a first projection face and a second projection face and smaller than a second predetermined angle determined based on the projection direction toward the boundary to be the correction amount for the trapezoidal distortion at one of the first predetermined angle and the second predetermined angle or less.