The 1973 Cincinnati Open was a tennis tournament played on outdoor clay courts at the Coney Island in Cincinnati, Ohio in the United States that was part of the 1973 Commercial Union Assurance Grand Prix. The tournament was held from August 6 through August 12, 1973. Ilie Năstase won the singles title.
Ilie Năstase defeated Manuel Orantes 5–7, 6–3, 6–4
John Alexander / Phil Dent defeated Brian Gottfried / Raúl Ramírez 1–6, 7–6, 7–6