Provided is an auxiliary sheave device with a simple and lightweight structure and a crane including the same. The auxiliary sheave device, provided in the crane including a derrick member guy line, includes an auxiliary sheave frame and an auxiliary sheave guy line supporting the auxiliary sheave. The derrick member guy line is connected to the distal end portion of the derrick member. The auxiliary sheave frame is attached to the distal end portion of the derrick member so as to be capable of making rotational movement and taking a projecting posture of projecting in the distal end direction from the distal end portion of the derrick member. The auxiliary sheave guy line is connected to the distal end portion of the auxiliary sheave frame and a guy line connection portion of the derrick member so as to keep the auxiliary sheave frame in the projecting posture.