A turbine blade including an airfoil portion having a leading edge, a trailing edge, and a pressure surface and a suction surface extending between the leading edge and the trailing edge. The airfoil portion internally forming a cooling passage, which includes first and second cooling passages, and a plurality of outflow passages each having one end which opens to a merging portion formed by connecting an end portion of the first cooling passage on a side of the trailing edge and an end portion of the second cooling passage on the side of the trailing edge, and another end which opens to the trailing edge. The first cooling passage and the second cooling passage are divided by a partition member disposed in the airfoil portion. The cooling passage includes pressure side pin fins in the first cooling passage, and suction side pin fins in the second cooling passage.