HEAVY DUTY TIRE

Provided is a heavy duty tire having improved cut resistance during high-load and high-speed running. Included is a heavy duty tire which includes a sidewall including a sidewall rubber composition, the sidewall rubber composition containing at least one isoprene-based rubber, at least one polybutadiene rubber, and at least one oxidized carbon black having an average particle size of 30 nm or less; the sidewall rubber composition containing, based on 100% by mass of the rubber components therein, at least 5% by mass but less than 50% by mass of the at least one polybutadiene rubber; the sidewall rubber composition satisfying the following relationships (1) and (2): (1) Amount of isoprene-based rubber > Amount of polybutadiene rubber wherein "Amount of isoprene-based rubber" and "Amount of polybutadiene rubber" represent the amounts (% by mass) of the at least one isoprene-based rubber and the at least one polybutadiene rubber, respectively, based on 100% by mass of the rubber components in the sidewall rubber composition; (2) Thickness at widest point > -0.14 x Amount of polybutadiene rubber + 10.0 wherein "Thickness at widest point" represents the thickness (mm) of the sidewall at the widest point, and "Amount of polybutadiene rubber" represents the amount (% by mass) of the at least one polybutadiene rubber based on 100% by mass of the rubber components in the sidewall rubber composition.