An electric hydraulic actuator is provided with an electric motor and a gear pump driven in rotation by the electric motor. The electric motor includes a motor housing and a rotating shaft supported by the motor housing so as to be freely rotatable. The gear pump has a drive gear into which the rotating shaft of the electric motor is inserted and a driven gear meshed with the drive gear. A pump housing is configured to accommodate the drive gear and the driven gear on one end and has an installation concave portion open at the other end for accommodating part of the motor housing. The motor housing is attached to the pump housing with a gap formed between the motor housing and the pump housing in a radial direction of the rotating shaft. The gap includes an O-ring to elastically support the motor housing in the radial direction.