A heavy duty tire comprising: bead portions; sidewall portions continuous to the respective bead portions; a tread portion to be in contact with a road surface; and buttress portions each extending inward in a tire radial direction from a corresponding tread end portion of the tread portion and continuous to a corresponding one of the sidewall portions, the tread end portion being located on an outer side, in a width direction, of the tread portion, wherein in the tread portion, a plurality of lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) intersecting with a tire circumferential direction and land portion blocks (100, 200, 300, 400, 500, 600, 700, 800) defined by the lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) are formed, at least one of end portions of each lateral groove portion (40A, 41A, 42A, 43A, 840A, 840B) opening to a tread end, the land portion blocks (100, 200, 300, 400, 500, 600, 700, 800)each having a side surface (101, 201, 301, 401, 501, 601, 701, 801) intersecting with the width direction of the tread portion, characterized in that a length, in the tread width direction, of each of the land portion blocks (100, 200, 300, 400, 500, 600, 700, 800) decreases from one side to the other side in the tire circumferential direction, the length, in the tread width direction, of the land portion block (100, 200, 300, 400, 500, 600, 700, 800) is a length from a groove end reference line extending in the tire circumferential direction to the tread end, and the groove end reference line is defined by inner ends, in the tread width direction, of the respective lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) adjacent to each other in the tire circumferential direction with the land portion block (100, 200, 300, 400, 500, 600, 700, 800) interposed therebetween. bead portions; sidewall portions continuous to the respective bead portions; a tread portion to be in contact with a road surface; and buttress portions each extending inward in a tire radial direction from a corresponding tread end portion of the tread portion and continuous to a corresponding one of the sidewall portions, the tread end portion being located on an outer side, in a width direction, of the tread portion, wherein in the tread portion, a plurality of lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) intersecting with a tire circumferential direction and land portion blocks (100, 200, 300, 400, 500, 600, 700, 800) defined by the lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) are formed, at least one of end portions of each lateral groove portion (40A, 41A, 42A, 43A, 840A, 840B) opening to a tread end, the land portion blocks (100, 200, 300, 400, 500, 600, 700, 800)each having a side surface (101, 201, 301, 401, 501, 601, 701, 801) intersecting with the width direction of the tread portion, characterized in that a length, in the tread width direction, of each of the land portion blocks (100, 200, 300, 400, 500, 600, 700, 800) decreases from one side to the other side in the tire circumferential direction, the length, in the tread width direction, of the land portion block (100, 200, 300, 400, 500, 600, 700, 800) is a length from a groove end reference line extending in the tire circumferential direction to the tread end, and the groove end reference line is defined by inner ends, in the tread width direction, of the respective lateral groove portions (40A, 41A, 42A, 43A, 840A, 840B) adjacent to each other in the tire circumferential direction with the land portion block (100, 200, 300, 400, 500, 600, 700, 800) interposed therebetween.