Erin is a town in Wellington County, approximately 80 kilometres (50 mi) northwest of Toronto, Ontario, Canada. Erin is bordered by the Town of Caledon, Ontario to the east, the Town of Halton Hills to the south, the Township of Guelph/Eramosa to the west and the Township of East Garafraxa to the north.

Wellington County is a county located in Southwestern Ontario, Canada and is part of the Greater Golden Horseshoe. The county, made up of two towns and five townships, is predominantly rural in nature. However many of the residents in the southern part of the county commute to urban areas such as Guelph, Kitchener, Waterloo, Brampton, Mississauga, Toronto and Hamilton for employment. The northern part of the county is made up of mainly rural farming communities, except for a few larger towns such as Mount Forest and Arthur. According to the 2021 census, the population of the county was 241,026.