Abstract: An outboard motor is provided which includes, in an engine compartment defined by an engine hood, an engine, an intake manifold including a plurality of intake branch pipes connected to a plurality of intake ports of the engine, and a throttle body connected to an intake inlet of the intake manifold. A negative pressure detection hole that opens within the intake manifold, is provided in the outer wall of the intake manifold, and a negative intake pressure sensor that is fixed to the outer wall is positioned in the negative pressure detection hole.