A tire tester includes a rotary member, a tire support mechanism, and an actuator configured to advance and retreat at least one of the rotary member and the tire support mechanism with respect to the other. The tire support mechanism includes a main frame connected with the actuator, a subframe supporting an axle extending in a second direction orthogonal to a first direction in which the rotary member or the tire support mechanism advances and retreats with the actuator, and movably attached to the main frame such that a distance of the subframe from the main frame decreases and increases in a direction crossing the first direction; and at least one measurement unit provided between the main frame and the subframe.