A flame retardant rubber composition includes (A) an ethylene/.alpha.-olefin random copolymer, (B) an unsaturated nitrile/conjugated diene rubber, and (D) surface-treated natural magnesium hydroxide or includes (A) an ethylene/.alpha.-olefin random copolymer, (B) an unsaturated nitrile/conjugated diene rubber, (C) a hydrogenated diene polymer, and (D) surface-treated natural magnesium hydroxide. Since the rubber composition and rubber product have good flame retardance, weather resistance, and oil resistance, as well as excellent mechanical characteristics, they are useful for various applications such as a roll, belt, and sealing material for copying machines, an electric wire coating material, and hoses.