An image forming apparatus includes an image forming unit and a re-conveyor. The re-conveyor includes a first bevel gear, a second bevel gear, a first re-conveying roller, a shaft member, a first engaged member, a second engaged member, and an engaging member. When the second bevel gear is rotated in a rotational direction by a driving force transmitted from the first bevel gear, the engaging member is moved to a second position and engaged with the first and second engaged members to rotate the shaft member in a rotational direction. When the shaft member is rotated in the rotational direction by a driving force transmitted from the first re-conveying roller, the engaging member is moved to a first position, disengaged from the second engaged member, and engaged with the first engaged member to interrupt transmission of the driving force from the shaft member to the second bevel gear.