In an outboard motor, an engine is mounted to an upper portion of an engine holder. A crank shaft is vertically disposed in a crank case of the engine. A plurality of cylinders are arranged in a cylinder block of the engine in parallel with each other in a vertical direction. An oil pan is disposed in the engine holder, and a balancing device is mounted to a bottom surface of the cylinder block facing the oil pan. The cylinder block is disposed between the crank case and a cylinder head. The bottom surface of the cylinder block is recessed. In this recessed portion, a balancing device is disposed.