The trailer hitching coupler of this invention includes a body having a horizontally disposed body plate, a dome fastened on the lower side of the forwardmost terminal end of the body plate to operably engage a hitching ball, and a pair of parallelly upstandingly disposed cam-supporting walls fastened to the upper-most terminal side of the body plate from the rearwardmost terminal side of the dome to the rearwardmost terminal end of the body plate. The coupler also includes a cam assembly carried between the cam-supporting walls distally from the rearwardmost terminal end of the dome. The cam assembly includes an eccentric-type cam having portions of its cam axis projecting through each of the cam-supporting walls, a cam follower having a centrally disposed hole which is operable to ride about the outer circumference of the cam, and an actuator arm fastened to the outwardly projecting portions of the cam axis. The actuator arm is provided with locking means operable to lock the cam assembly when the assembly is in engagement with the hitching ball.
