The Astor Place Riot occurred on May 10, 1849, at the now-demolished Astor Opera House in Manhattan and left between 22 and 31 rioters dead, and more than 120 people injured. It was the deadliest to that date of a number of civic disturbances in Manhattan, which generally pitted immigrants and nativists against each other, or together against the wealthy who controlled the city's police and the state militia.

The Astor Opera House, also known as the Astor Place Opera House and later the Astor Place Theatre, was an opera house in Manhattan, New York City, located on Lafayette Street between Astor Place and East 8th Street. Designed by Isaiah Rogers, the theater was conceived by impresario Edward Fry, the brother of composer William Henry Fry, who managed the opera house during its entire history.