A mounting assembly of a scooter seat, and a scooter. The mounting assembly comprises a mounting base (120), a supporting block (130), and a fastener; the mounting base (120) comprises a top plate (122) and two side plates (123) fixedly provided on two opposite sides of the top plate (122); mounting holes for fixing the scooter seat (900) are provided on the top plate (122); the two side plates (123) are clamped on the scooter body; the top plate (122) is provided on a footboard of the scooter body; the supporting block (130) is interposed between the scooter body and the side plates (123); the fastener is provided on the side plates (123) and tightly locks the supporting block (130) to enable the supporting block (130) to be fastened on the scooter body.