This optical scanning actuator can improve yield and assembly efficiency. An optical scanning actuator (10) includes a piezoelectric element (14) that is joined to a displaceably supported emission end (11a) of an optical fiber (11) and displaces the emission end (11a) in a direction perpendicular to an optical axis direction of the optical fiber (11) by expanding and contracting in the optical axis direction. The piezoelectric element (14) includes an identifier (16) for identifying a polarization direction, the identifier (16) being formed physically.