An adjustable trailer hitch assembly includes a shank configured for insertion into a vehicle receiver and a channel member extending from the shank. A ball mount is receivable within the channel member and is selectively positionable at different vertical heights. The channel member includes a plurality of longitudinal guide members, and the ball mount includes a non-circular body having a plurality of longitudinal slots configured to receive the guide members. Engagement between the guide members and the slots constrains the ball mount against rotational movement relative to the channel member while permitting removal and reinsertion of the ball mount in selected angular orientations. A transverse pin retains the ball mount at a selected height and angular orientation within the channel member.