A sheet processing apparatus includes: a pressing member that presses a fold part of a bundle of folded sheets so as to perform fold-enhancing; and a moving unit that moves a pressing position of the pressing member in a direction of a fold of the bundle of sheets. The moving unit starts pressing at an area located inside one end of the bundle of sheets while moving at a first velocity, and releases the pressing after passing through other end of the bundle of sheets during a forward movement, and starts pressing at an area located inside the other end of the bundle of sheets while moving at a second velocity that is higher than the first velocity, and passes through the one end of the bundle of sheets during a backward movement.