A developer supply member, a developing unit, and an image forming apparatus are provided that maintain high-quality image forming. The developer supply member includes: a rotation shaft; a base material which covers the rotation shaft and has a closed-cell foam structure containing a silicone rubber as a main constituent; and a coating film formed on an outer surface of the base material. The developer supply member satisfies an expression of T≧−0.15×H+9.6, and 54≦H≦69, where T is a thickness of the coating film measured in micrometers and H is Asker F hardness measured in degrees on a surface of the coating film.