In a throttle opening detecting apparatus for a saddle riding vehicle which includes a handle cover, a handle switch group, and a handlebar, and in which a throttle opening sensor fixed to the handlebar and configured to detect a displacement of a rotor in a sensor case is included in the handle cover, at least one switch of the handle switch group is disposed at a position facing the sensor case in the handle cover, and the sensor case has a step portion formed on a side surface thereof on a side opposite to a throttle pipe rotated integrally with the rotor.