Provided is a printing apparatus that prevents a print medium from buckling during discharging, a method of controlling a printing apparatus, and a storage medium. In the case where the print conveyance speed determined by the print mode is higher than or equal to the specified speed, the print medium after printing is conveyed to the discharging tray at the print conveyance speed, and in the case where the print conveyance speed determined by the print mode lower than the specified speed, the print medium after printing is conveyed to the discharging tray at the specified speed increased from the print conveyance speed.