The Commissariat Building Bytown Museum is a small museum in Ottawa located on the lower locks of the Rideau Canal at the Ottawa River just below Parliament Hill.The museum was opened in 1917 by the Women’s Canadian Historical Society of Ottawa (WCHSO) to house the collection of artifacts that the society had amassed since its founding in 1898. The museum's exhibits follow the early history of the city, originally known as Bytown, and the construction of the Rideau Canal.
The museum is housed in a stone building designed by Thomas McKay in the Georgian style. It was commissioned by the British military in 1827 as a sturdy supply storehouse and treasury. At the time, it was one of the largest buildings in town. It remained a government storehouse until 1951 when it became the home of the Bytown Museum.The original features include a stone vault that dates from 1841. The museum was included among other architecturally interesting and historically significant buildings in Doors Open Ottawa, held June 2 and 3, 2012.
Heritage Trust erected a plaque for The Commissariat Building 1827 In the lobby of the Bytown Museum, beside the third lock of the headlocks of the canal, between Parliament Hill and the Château Laurier, off Elgin Street, Ottawa. "Distinguished by skilful masonry and solid construction, the Commissariat building provides an excellent example of the workmanship of the Scottish stonemasons employed by Colonel By to work on the Rideau Canal.
It was investigated by the Girly Ghosthunters for any paranormal activity within its walls. It was shown as the fourth episode, of thirteen, of the named show in 2005.