A golf ball resin composition includes (A) (I) an olefin-C3-8 α,β-unsaturated carboxylic acid copolymer or a metal neutralization product thereof and/or (II) an olefin-C3-8 α,β-unsaturated carboxylic acid-C3-8 α,β-unsaturated carboxylic acid ester terpolymer or a metal neutralization product thereof; (B) isocyanuric acid or a haloisocyanuric acid; and (C) a fatty acid or a fatty acid metal salt. When this resin composition is used as a cover material, the paint film adhesion between the cover material and various types of paint, including urethane-based paints, is excellent, enabling various properties of the golf ball to be improved.