To provide an outboard motor including a clutch device that improves durability of an engaging convex part and an engaging concave part in engaging a forward gear or a backward gear with a dog gear or in transmitting drive power.

The outboard motor 10 includes a clutch device 25 including a pair of forward and backward gears 31 and 33 which are always driven in opposite directions by a drive shaft 21 driven by a drive part, and a dog gear 35 arranged round an output shaft 29, wherein a plurality of engaging convex parts 31a, 33a and engaging concave parts 36a which can be fitted to each other are provided, and wherein the dog gear is moved in one axial direction, and is thereby engaged with one of the forward and backward gears. The drive shaft includes a drive gear 23. The forward gear and the backward gear include input gears 31c, 33c always engaged with the drive gear. 7 to 10 engaging concave parts and 7 to 10 engaging convex parts are arranged radially inside the input gear in a circumferential direction.