The structure is named for William Osgoode,[1] the first Chief Justice of Upper Canada (now the province of Ontario).

The portico of Osgoode Hall's east wing was built at the head of Toronto's York Street to serve as a terminating vista, though it is now obscured by trees planted on the building's lawn.

The building was designated a National Historic Site of Canada in 1979,[5][6] and by the City of Toronto under the Ontario Heritage Act in 1990.

Its distinctive iron gates are narrow and restrictive; it is a long-standing myth that they were designed to keep livestock out of the grounds of the hall.

The Great Library was designed by Cumberland and Storm (1857–1860) and features an ornate plaster ceiling, cork floors, an iron spiral staircase and etched glass windows.