An object of the present invention is to provide a resin composition for the golf ball that suppresses the bleed out of the low molecular weight material component, as well as improves the fluidity and repulsion performance. The present invention provides a golf ball forming resin composition comprising as a resin component, (A) a high melt viscosity resin; (B) a low melt viscosity ionomer resin having a melt viscosity (190° C.) ranging from 1 Pa·s to 10 Pa·s measured by a brookfield viscometer, in a ratio of (A) the high melt viscosity resin/(B) the low melt viscosity ionomer resin being 55 mass % to 99 mass %/45 mass % to 1 mass %; and (C) a metal ion source capable of neutralizing carboxyl groups of (A) the high melt viscosity resin and (B) the low melt viscosity ionomer resin, in an amount of from 0.1 part to 10 parts with respect to 100 parts by mass of a sum of (A) the high melt viscosity resin and (B) the low melt viscosity ionomer resin.