Abstract: An oil pump for an engine of an outboard motor of the type including a block with an output shaft extending therefrom is disclosed. The oil pump includes an oil pan comprising an outer housing defining an oil chamber and a pumping chamber therein. The oil pump includes a pumping mechanism for pumping oil from the oil chamber to the engine. The pumping mechanism is positioned within the pumping chamber, with the outer housing defining the pumping chamber acting as a pump housing therefor. The pumping mechanism is positioned on and driven by the output shaft of the engine which extends through the oil and pumping chambers of the oil pan. A recess in the pumping chamber accomodates a flywheel, which is also positioned on and driven by the output shaft of the engine.