The first federal riding of York East was created by the British North America Act of 1867. Called the East Riding of York, it consisted of the Townships of Markham, Scarborough, the Village of Yorkville and the portion of the Township of York lying east of Yonge Street. In 1882, it was redefined to consist of the townships of East York, Scarborough and Markham, and the villages of Yorkville and Markham.
In 1914, the East Riding of York was recreated out of York Centre and York South ridings, and was defined as consisting of the township of Scarboro, and the eastern portion of the city of Toronto south of Danforth Avenue and east of Pape Avenue. The electoral district was abolished in 1924 when it was redistributed between Toronto—Scarborough and York South ridings.
In 1933, the riding of York East was created from parts of York North and York South ridings, and was defined as consisting of the part of the county of York lying south of the township of Whitchurch, east of Yonge Street, and north of the city of Toronto, and including the village of Stouffville.
In 1947, it was redefined to consist of the part of the county of York lying south of the township of Markham, east of Yonge Street and north of the city of Toronto. In 1952, it was redefined to consist of the township of East York and the part of North York township bounded south of Lawrence Avenue and east of the town of Leaside and Leslie Street.
