A sheet detecting apparatus including: a sheet detecting member having a plurality of abutment surfaces in a peripheral direction thereof, the sheet detecting member being rotated by a conveyed sheet abutting against one of the plurality of abutment surfaces; a detection portion which operates in association with the sheet detecting member; a sensor which generates a signal based on a position of the detection portion; and an urging portion which generates an urging force for positioning the one of the plurality of abutment surfaces of the sheet detecting member in a waiting position in which the leading edge of a sheet conveyed by a conveying portion abuts against the one of the plurality of abutment surfaces, and thereafter the urging portion switching the urging force to an urging force for positioning, in the waiting position, another one of the plurality of abutment surfaces against which a succeeding sheet abuts.