Locust Hill only became a place of significance with the arrival of the Ontario and Quebec Railway in the 1884, linking Toronto with Peterborough.

Area business leaders from Whitevale and Green River petitioned to create a railway station at what is now Locust Hill.

The hamlet and station were named after the farm of William and Esther Reesor Armstrong, where locust trees were a prominent feature.

[1] Locust Hill was one of the busiest stations on the Toronto-Perth line and was built on the St Clair Farm owned by Captain William Button on the northwest side of Highway 7.

Locust Hill had a small number of retail businesses along Highway 7: In 1856, a Methodist Church as well[7] A brick schoolhouse, SS#21, was built in 1864 on east side of Reesor Road north of Highway 7 and remained in use to the 1960s, converted to residential use and now partially repaired to the original configuration by Toronto Region Conservation Authority in 2017.