An optical scanning device includes a light source, a deflector that deflects a light beam from the light source, a first optical system that guides the light beam to the deflector, a second optical system that guides the light beam from the deflector to a surface to be scanned, and a housing that holds the light source and the deflector. At least one optical element included in the first optical system or the second optical system is attached to the housing via an intermediate member. The optical element is adjustable with respect to the intermediate member. The number of directions in which the optical element can be adjusted is two or more.