A variable valve mechanism includes a first cam and a second cam, a main arm that drives a valve when swinging, a first sub arm that swings when pressed by the first cam, a second sub arm that swings when pressed by the second cam, and a switch device. The switch device includes a first switch pin that moves between a first coupled position between the main arm and the first sub arm and a first uncoupled position, and a second switch pin that moves between a second coupled position between the main arm and the second sub arm and a second uncoupled position. Both switch pins are arranged so as to be displaced from each other in positions where these switch pins do not overlap at least during a base circle phase in which base circles of both cams act.