A turbine blade includes: an airfoil body; a cooling passage extending along a blade height direction inside the airfoil body; and a plurality of turbulators disposed on an inner wall surface of the cooling passage and arranged along the cooling passage. The airfoil body has a first end portion and a second end portion which are opposite end portions in the blade height direction. A passage width of the cooling passage in a suction-pressure direction of the airfoil body at the second end portion is greater than a passage width of the cooling passage at the first end portion. A height of the plurality of turbulators increases from a first end portion side to a second end portion side in the blade height direction.