Abstract: A trailer hitch locking device for securing a trailer having a ball type hitch includes a rigid U-shaped frame member having a central lower mounting member, an upper pin shield, a locking pin having a flattened locking end, a shaft and a pin head, the locking end engaging a cylindrical security lock which engages the locking pin through a hole in the frame member, the cylindrical security lock being surrounded by a lock security collar, preventing access to the entire cylindrical lock except for the outer surface of the cylindrical lock, exposed from the lock security collar, the pin head being sunken into a pin head recess in the frame member across from the lock security collar. The pin head access prevents access to the pin, the upper pin shield prevents access to the shaft of the pin and the cylindrical security lock and lock security collar preventing access to the locking end of the pin, the pin preventing removal of the device from the applied ball type hitch of the trailer.