A three-piece solid golf ball having a solid core, an intermediate layer enclosing the solid core, and a cover layer enclosing the intermediate layer and having a large number of dimples formed in its surface, characterized in that the core deforms as much as 3.4 to 4.1 mm under a load which changes from 10 kg to 130 kg, the intermediate layer has a surface hardness of 64 to 69 in terms of Shore D hardness, the cover layer is formed mainly from thermoplastic polyurethane such that it has a lower hardness than the intermediate layer, with the difference in hardness between the cover layer and the intermediate layer being 10 to 16 in terms of Shore D hardness, the intermediate layer and the cover layer have a total thickness of 2.2 to 3.0 mm, the cover layer has a thickness of 0.8 to 1.3 mm, and the dimples have at least four different diameters and/or depths, with the average depth being 0.14 to 0.17 mm, and amount to 250 to 390 in all. The three-piece solid golf ball exhibits adequate spin performance by iron shot and approach shot. It also exhibits good flying performance and durability.