A heavy duty tire comprising a carcass extending from a tread part through a sidewall part to a bead core of a bead part and a belt layer arranged outside in a tire radial direction of the carcass and inside of the tread part, wherein the belt layer is formed by a belt ply comprising a first belt layer, a second belt layer, and a third belt layer which are laminated in order from inside in the tire radial direction, wherein the tread has a plurality of main grooves extending continuously in a tire circumferential direction, wherein the tread comprises a cap rubber layer constituting a tread surface and a base rubber layer adjacent to inside in a tire radial direction of the cap rubber layer, wherein the cap rubber layer and the base rubber layer are composed of a rubber composition comprising a rubber component, wherein the rubber component constituting the cap rubber layer comprises an isoprene-based rubber, a styrene-butadiene rubber, and a butadiene rubber, wherein the rubber composition constituting the cap rubber layer comprises 30 parts by mass or more of silica having a nitrogen adsorption specific surface area (N 2 SA) of 180 m 2 /g or more based on 100 parts by mass of the rubber component, wherein the N 2 SA of silica is a value measured by a BET method according to ASTM D3037-93, characterised in that a tan δ of the rubber composition constituting the base rubber layer at 70°C is 0.04 to 0.07, wherein the "70°C tan δ" refers to a loss tangent tan δ under a condition of a temperature at 70°C, an initial strain of 10%, a dynamic strain of ± 2%, and a frequency of 10 Hz, and in that the rubber component constituting the cap rubber layer comprises 65% by mass or more of isoprene-based rubber, and a content of the styrene-butadiene rubber in 100% by mass of a total amount of the styrene-butadiene rubber and the butadiene rubber is 50% by mass or more. wherein the belt layer is formed by a belt ply comprising a first belt layer, a second belt layer, and a third belt layer which are laminated in order from inside in the tire radial direction, wherein the tread has a plurality of main grooves extending continuously in a tire circumferential direction, wherein the tread comprises a cap rubber layer constituting a tread surface and a base rubber layer adjacent to inside in a tire radial direction of the cap rubber layer, wherein the cap rubber layer and the base rubber layer are composed of a rubber composition comprising a rubber component, wherein the rubber component constituting the cap rubber layer comprises an isoprene-based rubber, a styrene-butadiene rubber, and a butadiene rubber, wherein the rubber composition constituting the cap rubber layer comprises 30 parts by mass or more of silica having a nitrogen adsorption specific surface area (N 2 SA) of 180 m 2 /g or more based on 100 parts by mass of the rubber component, wherein the N 2 SA of silica is a value measured by a BET method according to ASTM D3037-93, characterised in that a tan δ of the rubber composition constituting the base rubber layer at 70°C is 0.04 to 0.07, wherein the "70°C tan δ" refers to a loss tangent tan δ under a condition of a temperature at 70°C, an initial strain of 10%, a dynamic strain of ± 2%, and a frequency of 10 Hz, and in that the rubber component constituting the cap rubber layer comprises 65% by mass or more of isoprene-based rubber, and a content of the styrene-butadiene rubber in 100% by mass of a total amount of the styrene-butadiene rubber and the butadiene rubber is 50% by mass or more.