The provincial riding of York South first came into existence for the 1926 Ontario election. It was slightly smaller than the federal riding but covered much of the same area. For most of the period after World War II, it was a bastion of the Ontario CCF and its successor, the NDP, being the riding of three CCF/NDP leaders in the Ontario legislature, Ted Jolliffe, Donald C. MacDonald and Bob Rae.
When the government of Mike Harris changed Ontario's electoral law so that federal and provincial ridings matched, most of York South was merged into York South—Weston. Smaller portions of the old riding became parts of Parkdale—High Park and Davenport.
^For a listing of each MPP's Queen's Park curriculum vitae see below:
For Leopold Macaulay's Legislative Assembly information see "Leopold Macaulay, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2012-03-18.
For Ted Jolliffe's Legislative Assembly information see "Edward Bigelow Jolliffe, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2011-11-29.
For Howard Sale's Legislative Assembly information see "Howard Julian Sale, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2011-11-29.
For William Beech's Legislative Assembly information see "William George Beech, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2011-11-29.
For Donald C. MacDonald's Legislative Assembly information see "Donald Cameron MacDonald, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2012-03-18.
For Bob Rae's Legislative Assembly information see "Bob Keith Rae, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2012-03-18.
For Gerard Kennedy's Legislative Assembly information see "Gerard Kennedy, MPP". Parliamentary History. Toronto: Legislative Assembly of Ontario. 2012. Retrieved 2012-03-18.
^ abCanadian Press (1929-10-31). "Provincial Election Results". The Globe. Toronto. p. 5.
^"Detailed Election Results". The Globe. Toronto. 1934-06-21. p. 3.
^"Ontario Voted By Ridings". The Toronto Daily Star. Toronto. 1937-10-07. p. 5.