The invention provides a resin composition for golf balls having excellent resilience, flexibility and fluidity, and golf balls having excellent resilience and shot feel. The resin composition comprises: (A) at least one selected from the group consisting of (a-1) a binary copolymer of an olefin and a C3-8 α,β-unsaturated carboxylic acid, (a-2) a metal ion-neutralized product of a binary copolymer of an olefin and a C3-8 α,β-unsaturated carboxylic acid, (a-3) a ternary copolymer of an olefin, a C3-8 α,β-unsaturated carboxylic acid, and an α,β-unsaturated carboxylic acid ester, and (a-4) a metal ion-neutralized product of a ternary copolymer of an olefin, a C3-8 α,β-unsaturated carboxylic acid, and an α,β-unsaturated carboxylic acid ester; (B) a compound containing a hydrocarbon chain, a cationic moiety, and an anionic moiety in its molecule; and (C) a nonionic surfactant, wherein a total degree of neutralization expressed by the following equation is 50-300 mol %: