A seat reclining apparatus includes a first member attached to one of a seatback frame and a seat cushion frame and including engaged portions, a second member attached to the other one of the seatback frame and the seat cushion frame, and a cam member bringing engaging members to move in a radial direction so as to engage or disengage between the engaged portions and the engaging members. The cam member includes a pivot axis arranged in such a manner that a simultaneous engagement or disengagement is achieved among each engaging member and the corresponding engaged portion when center axes of the first member and the second member are offset to each other by an amount corresponding to a clearance formed between the first member and the second member because of a load applied to the seatback frame in a case where a seatback is tilted.
