The invention provides a golf ball material which is a resin mixture composed of (a) an olefin-methacrylic acid copolymer and/or an olefin-methacrylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 120,000 to 200,000 and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of from 4.0 to 7.0, or a metal neutralization product thereof, (b) an olefin-acrylic acid copolymer and/or an olefin-acrylic acid-unsaturated carboxylic acid ester copolymer having a weight-average molecular weight (Mw) of from 150,000 to 220,000 and a weight-average molecular weight (Mw) to number-average molecular weight (Mn) ratio of from 5.5 to 8.5, or a metal neutralization product thereof, (c) an organic acid or a metal salt thereof, and (d) a basic inorganic metal compound for neutralizing at least 70 mol % of acid groups in components (a) to (c), which resin mixture has a Shore D hardness of from 30 to 60. The golf ball material of the invention is a low-hardness material. Golf balls in which an injection molding of the golf ball material is used as a cover material have an excellent rebound and durability.