The Grand Opera House was an opera house and concert hall located in Toronto, Ontario, Canada.
Opened in 1874 on Adelaide Street West, west of Yonge Street, the Grand Opera House was Toronto's premier concert hall during the late 19th century. Designed in the Second Empire style with 1750 seats, the hall was the first in the city to feature gaslights that could all be switched on or off simultaneously with one electric switch. The Grand Opera House's stage hosted some of the era's best-known performers, including actors Maurice Barrymore, Sarah Bernhardt and Sir Henry Irving, soprano Emma Albani, as well as Italian baritones Giuseppe Del Puente and Antonio Galassi. Visiting lecturers included Oscar Wilde. During its initial years, the Grand Opera House was managed by Charlotte Morrison, a former actress, and the guiding force at that time behind Toronto's opera and theatre scenes. Morrison has been described as the "Ed Mirvish of her time".
The Grand Opera House suffered a number of fires, including a major blaze in 1879 that killed a stage-carpenter, as well as his wife and infant daughter. Although the hall was restored and reopened after each fire, it slowly fell into neglect with the arrival of the vaudeville age in the 1900s, which brought with it newer and more modern vaudeville theatres to Toronto, most notably the Loews and Winter Garden Theatres on Yonge Street.
In 1919, the Grand Opera House became embroiled in an infamous and widely reported criminal investigation. On December 2, the Grand Opera House's owner at the time, Ambrose Small, deposited a cheque for a million dollars in a nearby bank, and went missing later that day. Before his disappearance, Small already had a reputation in Victorian Toronto as a gambler, and booked less reputable, more titillating shows to his string of theatres, including the Grand Opera House. The newspapers published every known detail of the police investigation into his disappearance, and soon it was revealed that Small had kept a secret sex room at the Grand Opera House, where he entertained numerous mistresses. The scandal further tarnished the Grand Opera House's standing in a strait-laced city then known as the Methodist Rome.