Apparatus, methods, and other examples associated with a hitch ball coupler are described herein. In one example, a coupler includes a body and a cap. The body and cap are pivotally connected on a first end. The body includes a first recess and a shoulder. The cap is selectively moveable between a closed position and an open position. The cap includes a second recess that selectively forms a socket with the first recess, and an arm extending from a second end that engages the shoulder when the cap is in the open position.