Middlesex County Court House, Historic courthouse in London, Canada.

Middlesex County Court House at 399 Ridout Street North is a three-storey parged brick building with a stone foundation housing the cell blocks. Its classical composition has a central pavilion and two side wings ending in octagonal corner towers, with tall lancet windows, secondary square windows and crenellations. It was built from 1827 to 1829 to designs by Toronto architect John Ewart and held the court, jail and police offices.

Designed by Toronto architect John Ewart in the Gothic Revival style, the Middlesex County Court House was built from 1827 to 1829 using locally quarried stone. It originally housed the court, the jail and police administrative offices. In 1955 it was designated a National Historic Site because it is a very early example of the Gothic Revival style, pre-dating the Houses of Parliament in England.

The courthouse's castle-like look comes from crenellations, octagonal corner towers and tall lancet windows, all in the Gothic Revival style of architect John Ewart. The walls are squared brick covered with mortar to imitate stone, resting on a stone foundation that housed the cell blocks. The building held the court, jail and police offices together.

The building stands at 399 Ridout Street North, south of Dundas Street and north of King Street. Its exterior and the surrounding landscape are protected by an Ontario Heritage Trust conservation easement, so the grounds are best viewed from the public street. The sources describe no visitor tours or opening hours, so check locally before planning a look inside.

The 1955 National Historic Site designation rests on a comparison: this courthouse predates England's Houses of Parliament as a Gothic Revival public building. The exterior and the landscape around it are also held under an Ontario Heritage Trust conservation easement, and the building is designated under Part 4 of the Ontario Heritage Act.