To reduce the number of components in a vehicle transmission that includes a mechanism for making a seamless shift between a low-speed-side gear shift stage and a high-speed-side gear shift stage.

A vehicle transmission includes a first engaged member 110 fixed to a first idling gear G1o, a second engaged member 120 fixed to a second idling gear G2o, a first engaging member 130 provided on an output shaft A3 so as to be incapable of relative rotation but so as to be movable between an engagement position of engaging with the first engaged member 110 and a non-engagement position, a second engaging member 140 provided on the output shaft A3 so as to be incapable of relative rotation but so as to be movable between an engagement position of engaging with the second engaged member 120 and a non-engagement position, and a driving device for driving the first engaging member 130 and the second engaging member 140. Owing to this configuration, it is possible to selectively establish any mode of a low-speed mode in which only the first engaging member 130 is engaged, a high-speed mode in which only the second engaging member 140 is engaged, and an intermediate mode in which both of the first engaging member 130 and the second engaging member 140 are engaged between the low-speed mode and the high-speed mode.