Abstract: A fifth wheel trailer hitch adaptor apparatus including a fifth wheel device including a housing having a stem projecting therefrom for telescopical receipt in a rearwardly opening square tube of a towing vehicle and having a fifth wheel yoke plate formed with a rearwardly extending, open ended, laterally outwardly diverging passage. An adaptor plate is provided and includes on its top side an upstanding hitch ball for receipt in the ball socket of a trailer and has a king pin on the bottom side thereof for sliding receipt into the passage for hitching to such fifth wheel device.