A shift drum angle detecting device includes: a first angle sensor configured to output a first sensor output value corresponding to a shaft rotational angle of a first sensor shaft integrally rotating with a shift drum; and a second angle sensor configured to output a second sensor output value corresponding to a shaft rotational angle of a second sensor shaft rotating at an increased speed as a result of a speed increasing mechanism increasing the rotation of the first sensor shaft. A first sensor switching angle where the maximum value and the minimum value of the first sensor output value are switched and a second sensor switching angle where the maximum value and the minimum value of the second sensor output value are switched are set to be different from each other in rotational angle of the shift drum. Such device precisely detects any rotational angle of the shift drum.