Middlesex North was a federal electoral district in Ontario, Canada, that was represented in the House of Commons of Canada from 1867 to 1917.

The North Riding consisted of the Townships of McGillivray and Biddulph (taken from the County of Huron), and Williams East, Williams West, Adelaide, and Lobo.

In 1882, it was redefined add the township of Stephen and the villages of Ailsa Craig, Lucan, Exeter and Parkhill, and to exclude the townships of Adelaide and Lobo.

In 1903, it was redefined to consist of the townships of Adelaide, Biddulph, Lobo, McGillivray, Williams East and Williams West, the town of Parkhill and the villages of Ailsa Craig and Lucan.

This riding has elected the following members of Parliament: On Mr. Scatcherd's death, 15 April 1876: