Provided are a pitch actuator for a wind turbine generator and a wind turbine generator that can be prevented from losing their reliability. Provided are a cylinder (12) and a rod (13) that rotate a wind turbine rotor blade about an axis thereof relative to a rotor head to change a pitch angle; a cylinder bearing (14, 15) supporting the cylinder (12) so as to be rotatable relative to the rotor head about a first rotation axis (L1) extending substantially parallel to the axis of the wind turbine rotor blade and about a second rotation axis (L2) extending in a direction crossing both the first rotation axis (L1) and the axis of the cylinder (12) and the rod (13); and a rod bearing (16) rotatably supporting an end of the rod (13) on an end surface of the wind turbine rotor blade.