A rotation detecting apparatus includes a rotating member, detectors regarding a rotating direction of the rotating member, and a predetermined unit. Each detector detects whether a predetermined standard direction is included in detecting ranges different for each rotating member and outputs a result. The predetermined unit combines the detection result output from each detector and extracts an angle range. The predetermined unit specifies the rotating direction of the rotating member based on changes in the angle ranges extracted a plurality of times occurring in the plurality of times. The detecting range corresponding to each of the plurality of detectors is determined to be able to identify relative positions before and after a change from the angle range extracted by the predetermined unit to the angle range that is clockwise or counterclockwise apart a predetermined number or less to the angle range extracted, the predetermined number being two or more.