The invention provides a golf ball material which is a resin mixture composed of (a) an olefin-unsaturated carboxylic acid copolymer and/or an olefin-unsaturated carboxylic 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 4.3 to 6.6, or a metal neutralization product thereof, (b) an olefin-unsaturated carboxylic acid copolymer and/or an olefin-unsaturated carboxylic 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 6.8 to 9.5, 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 55. 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.