A sheet post-processing apparatus includes a cutting device for cutting a fore-edge portion of a center-folded bunch of sheets disposed in a position spaced from a sheet discharge outlet to eliminate the risk for inflicting a wound on the body of an operator, an end binding device for gathering sheets received from a carry-in entrance and performing binding processing in the end portion of a bunch of sheets, a saddle-stitching device for gathering sheets received from the carry-in entrance and performing binding processing in the center portion of a bunch of sheets, and a center-folding device for performing center-folding processing on the bunch of sheets subjected to the saddle-stitching processing. A cutting device is subjected to the center-folding processing. A second discharge outlet is disposed in the other side face of the apparatus frame to discharge the bunch of sheets subjected to the center-folding processing in the center-folding device.