A golf ball 2 includes a spherical core 4, a mid layer 6 positioned outside the core 4, and a cover 8 positioned outside the mid layer 6. The core 4 includes a spherical center 10 and an envelope layer 12 positioned outside the center 10. The center 10 has a diameter of 1 mm or greater and 15 mm or less. The center 10 has a JIS-C hardness H1, at its central point, of 20 or greater and 50 or less. The difference (H4−H3) between the JIS-C hardness H4 of the core 4 at its surface and the JIS-C hardness H3 of the envelope layer 12 at its innermost portion is equal to or greater than 10. The cover 8 has a flexural modulus of 300 MPa or greater and 1000 MPa or less, and has a tensile modulus of 400 MPa or greater and 1500 MPa or less.