There is provided an outboard motor (1), comprising: an intake valve (17) and an exhaust valve (18) provided to a cylinder head (14); a camshaft (20) arranged substantially vertically in the cylinder head to open and close the intake and exhaust valves; a valve operation characteristics changing device (29) hydraulically operated to change operation characteristics of at least one of the intake and exhaust valves; a selector valve (electromagnetic valve 27) for controlling an oil pressure provided to the valve operation characteristics changing device; and an exhaust passage component part (exhaust manifold 23) secured on a side of the cylinder head, wherein the selector valve is disposed at a position (space G) beside the cylinder head and overlapping with a top-end surface of the exhaust passage component part.