The present invention relates to a balancer and a washing machine including the same. The balancer includes at least two drive modules which provide a driving force; at least two gear rails having a ring shape which are gear-coupled to each of the drive modules and rotated; at least two balancing weights which move along a circumference of a drum by the rotation of each of the gear rails and change a center of gravity of the drum; a reception coil which generates power from a magnetic field formed by a transmission coil; and a guide case which accommodates at least the reception coil and the drive modules.