The 1974 Cincinnati Open was a tennis tournament played on outdoor hard courts at the Coney Island in Cincinnati, Ohio in the United States that was part of the 1974 Commercial Union Assurance Grand Prix. The tournament began on July 31, 1974. First-seeded Marty Riessen won the singles title.
Marty Riessen defeated Robert Lutz 7–6, 7–6
Dick Dell / Sherwood Stewart defeated Jim Delaney / John Whitlinger 4–6, 7–6, 6–2