A wheel module for an input device includes a circuit board, a wheel swinging member, and a wheel. A plurality of switch elements are installed on the circuit board. These switch elements are arranged between the circuit board and the wheel swinging member. The wheel is disposed on the wheel swinging member. When the wheel is moved downwardly relative to the wheel swinging member by a specified distance, an operating mode of the wheel module is switched from a rotating mode to a swinging mode. When the wheel module is operated in the rotating mode, the wheel is rotatable relative to the wheel swinging member. When the wheel module is operated in the swinging mode and the wheel is tilted in a specified direction, the wheel swinging member is synchronously swung relative to the circuit board to trigger a corresponding switch element.