Middlesex County, Ontario

Middlesex County
County (upper-tier)
County of Middlesex
Middlesex County courthouse, London
London Newbury Oneida 41 Strathroy-Caradoc Middlesex Centre Thames Centre North Middlesex Southwest Middlesex Lucan Biddulph Adelaide Metcalfe
Location of Middlesex census division
Coordinates: 43°00′N 81°30′W / 43.000°N 81.500°W / 43.000; -81.500
Country	Canada
Province	Ontario
Named for	Middlesex, England
County seat	London
Municipalities	List Adelaide-Metcalfe Lucan Biddulph Middlesex Centre Newbury North Middlesex Southwest Middlesex Strathroy-Caradoc Thames Centre
Area [1]
• Land	2,897.26 km2 (1,118.64 sq mi)
• Census division	3,317.76 km2 (1,280.99 sq mi)
	Land area excludes London
Population  (2021)[1]
• Total	78,239
• Density	27.0/km2 (70/sq mi)
• Census division	500,563
• Census division density	150.9/km2 (391/sq mi)
	Total excludes London
Time zone	UTC-5 (EST)
• Summer (DST)	UTC-4 (EDT)
Website	www.county.middlesex.on.ca

Middlesex County is a primarily rural county and census division in Southwestern Ontario, Canada. Landlocked, the county is bordered by Huron and Perth counties on the north, Oxford County on the east, Elgin County on the south, and Chatham-Kent and Lambton County on the west.

The county seat is the city of London, although the city is politically independent from the county. The Middlesex census division, which consists of the county together with the City of London and three First Nations reserves, had a population of 500,563 in 2021.^[1] Part of the county is also included in the London census metropolitan area.