Abstract: A plate lockup apparatus for a printing press includes a lockup table, a gripper plate, a cam shaft, a pin, and a compression coil spring. The lockup table is supported on a bottom surface of a gap in a circumferential surface of a cylinder to be movable forward/backward perpendicularly to the axis of the cylinder, and extends in the axial direction of the cylinder. The gripper plate is swingably and pivotally supported on the lockup table such that its gripper surface opposes the lockup table, and is constituted by a horizontal member extending in a circumferential direction of the cylinder and a vertical member extending in a radial direction of the cylinder to have a substantially L-shaped section. The cam shaft is disposed between the lockup table and the wall surface of the gap to be rotatable in the axial direction of the cylinder.