The Haymarket Opera Company's name derives from two historical sources: Chicago's 1886 Haymarket Riot and the establishment of the King's Theatre in London's Haymarket district in 1705. As a pivotal moment in the history of labor relations in "the city that works," the Haymarket Riot is engrained into the city's character. It is an historical moment that is quintessentially "Chicago." On May 4, 1886, there was a public gathering of workers in Chicago who were on strike for an eight-hour workday. Police attempted to disperse the protesters when an unknown person threw a bomb. The police then opened fire, killing several demonstrators and eight officers. The site of the incident was designated in 1992 as an historic landmark. The Haymarket Affair, as it became known, is remembered internationally each year on May Day.

The King's Theatre in the Haymarket district of London is inextricably linked with the history of 17th and 18th century music. Between 1711 and 1739, more than 25 operas by George Frederick Handel premiered there. In the early 19th century, the theatre hosted the opera company that was to move to the Theatre Royal, Covent Garden, in 1847, and presented the first London performances of Mozart's La clemenza di Tito, Così fan tutte, and Don Giovanni

HOC's name thus reflects its dual commitment to the city of Chicago and to the music of the 17th and 18th centuries.