A development device includes a casing storing development agent, a developing member that is rotatably supported in an opening of the casing and configured to hold development agent thereon, a first seal member that extends in a first direction parallel to a rotational axis of the developing member and has a base end at a side of the casing and a free end contacting an entire length, in the first direction, of the developing member, and an elastic member disposed between the casing and the free end so as to face the entire length, in the first direction, of the developing member. The elastic member presses the free end against the entire length, in the first direction, of the developing member.