A sheet stacking apparatus comprising: a sheet stacking portion on which a sheet discharged from a sheet discharge port is stacked; a cover portion configured to move to a closed position for covering the sheet discharge port and the sheet stacking portion and an open position for allowing taking out of the sheet stacked on the sheet stacking portion; a sheet pressing portion configured to move to a press-down position for pressing the sheet stacked on the sheet stacking portion and an apart position that is distant from the sheet stacked on the sheet stacking portion; and a movement-linking portion configured to cause the sheet pressing portion to move from the apart position to the press-down position upon an opening movement of the cover portion.