A wind turbine rotor, comprising: a plurality of wind turbine blades each including a suction surface and a pressure surface arranged opposite to each other, and a hub to which each of the plurality of wind turbine blades is mounted, wherein, around a location such that a chord length of each of the wind turbine blades is maximized which is included within a spanwise region of the wind turbine blade where a ratio of a radial position r of the wind turbine rotor to a radius R of the wind turbine rotor is not less than 0.1 and not more than 0.4, each of the wind turbine blades includes an airfoil (30; 30') having a first dimensionless value y max /t max of not less than 0.4 and not more than 0.46 and a second dimensionless value y f /y max of not less than 0.63 and not more than 0.71, where: the first dimensionless value y max /t max is a ratio of a maximum upper (suction-side) thickness y max being a maximum value of a distance between a chord and the suction surface to a maximum blade thickness t max being a maximum value of a distance between the suction surface and the pressure surface; and the second dimensionless value y f /y max is a ratio of a upper (suction-side) thickness y f to the maximum upper (suction-side) thickness y max, the upper (suction-side) thickness y f being a distance between the chord and the suction surface at a position in the chord direction at a distance of 0.3 x max from a leading edge when defining a position in the chord direction having the maximum upper (suction-side) thickness y max as being at a distance x max between the leading edge and the position in the chord direction having the maximum upper (suction-side) thickness y max; and a diameter of the wind turbine rotor is not less than 100 m. a plurality of wind turbine blades each including a suction surface and a pressure surface arranged opposite to each other, and a hub to which each of the plurality of wind turbine blades is mounted, wherein, around a location such that a chord length of each of the wind turbine blades is maximized which is included within a spanwise region of the wind turbine blade where a ratio of a radial position r of the wind turbine rotor to a radius R of the wind turbine rotor is not less than 0.1 and not more than 0.4, each of the wind turbine blades includes an airfoil (30; 30') having a first dimensionless value y max /t max of not less than 0.4 and not more than 0.46 and a second dimensionless value y f /y max of not less than 0.63 and not more than 0.71, where: the first dimensionless value y max /t max is a ratio of a maximum upper (suction-side) thickness y max being a maximum value of a distance between a chord and the suction surface to a maximum blade thickness t max being a maximum value of a distance between the suction surface and the pressure surface; and the second dimensionless value y f /y max is a ratio of a upper (suction-side) thickness y f to the maximum upper (suction-side) thickness y max, the upper (suction-side) thickness y f being a distance between the chord and the suction surface at a position in the chord direction at a distance of 0.3 x max from a leading edge when defining a position in the chord direction having the maximum upper (suction-side) thickness y max as being at a distance x max between the leading edge and the position in the chord direction having the maximum upper (suction-side) thickness y max; and a diameter of the wind turbine rotor is not less than 100 m. the first dimensionless value y max /t max is a ratio of a maximum upper (suction-side) thickness y max being a maximum value of a distance between a chord and the suction surface to a maximum blade thickness t max being a maximum value of a distance between the suction surface and the pressure surface; and the second dimensionless value y f /y max is a ratio of a upper (suction-side) thickness y f to the maximum upper (suction-side) thickness y max, the upper (suction-side) thickness y f being a distance between the chord and the suction surface at a position in the chord direction at a distance of 0.3 x max from a leading edge when defining a position in the chord direction having the maximum upper (suction-side) thickness y max as being at a distance x max between the leading edge and the position in the chord direction having the maximum upper (suction-side) thickness y max; and a diameter of the wind turbine rotor is not less than 100 m.