A resin composition for golf balls includes specific amounts of (A) polyurethane or polyurea and (B) an oxazoline group-containing acrylic polymer or an oxazoline group-containing styrene polymer. A golf ball having a core encased by a cover of one or more layers, wherein at least one cover layer is formed of this resin composition, exhibits a good adhesion between adjoining layers, enabling the ball to achieve a high scuff resistance without lowering the initial velocity of the ball.