A sheet detecting apparatus that detects a sheet has a lever member; a biasing portion that biases the lever member for a first position where the abutting surface abuts against the leading end of the sheet; a supporting mechanism that movably supports the lever member to move in an order of the first position, a second position, and a third position, while keeping a abutting surface of lever member facing upstream; an interlocking portion that interlocks with the lever member; and a detector that detects a position of the interlocking portion. The second position is a position to which the lever member moves by the sheet being conveyed against the biasing force of the biasing member, and the third position is a position where the abutting surface is positioned upstream in the sheet conveying direction of a position of the abutting surface at the second position and where the lever member abuts the surface of the sheet being conveyed and stands by to move to the first position when a trailing end of the sheet passes the lever member.