Abstract: A plate lockup device position detecting apparatus for a printing press includes first and second limit switches, and a series circuit. The first limit switch is provided in a gap of a plate cylinder and detects that a leading-side plate lockup device, a position of which is adjustable at least in one of vertical and horizontal directions of a plate, is restored to its origin position. The second limit switch is provided in the gap and detects that a trailing-side plate lockup device, a position of which is adjustable at least in one of the vertical and horizontal directions of the plate, is restored to its origin position. The series circuit detects that the plate lockup devices are restored to their origin positions from a logical product of the detection outputs from the first and second limit switches.