15th Parliament of Ontario
The 15th Legislative Assembly of Ontario was in session from October 20, 1919, until May 10, 1923, just prior to the 1923 general election. The majority party was the newly formed United Farmers of Ontario; they formed a coalition government with the 11 Labour MLAs. The party approached Ernest Charles Drury, who had not run in the election, to serve as party leader and premier. Drury was elected in a by-election held in Halton in 1920.
The majority of the United Farmers seats were won at the expense of the Conservative party, who had formed the government in the preceding assembly.
Nelson Parliament served as speaker for the assembly.
In 1924, the provincial treasurer was found guilty of conspiracy to defraud the government following a series of events known as the Ontario Bond Scandal.
| Riding | Member | Party |
| Addington | William David Black | Conservative |
| Algoma | Kenneth Spencer Stover | Liberal |
| Brant | Harry Corwin Nixon | United Farmers |
| Brant South | Morrison Mann MacBride | Labour |
| Brockville | Donald McAlpine | Liberal |
| Bruce North | William Henry Fenton | United Farmers |
| Bruce South | Frank Rennie | Liberal |
| Bruce West | Alexander Patterson Mewhinney | Liberal |
| Carleton | Robert Henry Grant | United Farmers |
| Cochrane | Malcolm Lang | Liberal |
| Dufferin | Thomas Kerr Slack | United Farmers |
| Dundas | William H. Casselman | United Farmers |
| Durham East | Samuel Sandford Staples | United Farmers |
| Durham West | William John Bragg | Liberal |
| Elgin East | Malcolm MacVicar | United Farmers |
| Elgin West | Peter Gow Cameron | United Farmers |
| Essex North | Alphonse George Tisdelle | United Farmers |
| Essex South | Milton C. Fox | United Farmers |
| Fort William | Henry Mills | Labour |
| Frontenac | Anthony McGuin Rankin | Conservative |
| Glengarry | Duncan Alexander Ross | United Farmers |
| Grenville | George Howard Ferguson | Conservative |
| Grey Centre | Dougall Carmichael | United Farmers |
| Grey North | David James Taylor | Liberal-United Farmers |
| Grey South | George Mansfield Leeson | United Farmers |
| Haldimand | Warren Stringer | United Farmers |
| Halton | John Featherstone Ford | United Farmers |
| Ernest Charles Drury | United Farmers | |
| Hamilton East | George Grant Halcrow | Labour |
| Hamilton West | Walter Rollo | Labour |
| Hastings East | Henry Ketcheson Denyes | United Farmers |
| Hastings North | John Robert Cooke | Conservative |
| Hastings West | William Henry Ireland | Conservative |
| Huron Centre | John M. Govenlock | Labour |
| Huron North | John Joynt | Conservative |
| Huron South | Andrew Hicks | United Farmers |
| Kenora | Peter Heenan | Labour |
| Kent East | James B. Clark | United Farmers |
| Manning William Doherty | United Farmers | |
| Kent West | Robert Livingstone Brackin | Liberal |
| Kingston | Arthur Edward Ross | Conservative |
| William Folger Nickle | Conservative | |
| Lambton East | Leslie Warner Oke | United Farmers |
| Lambton West | Jonah Moorehouse Webster | United Farmers |
| Lanark North | Hiram McCreary | United Farmers |
| Lanark South | William J. Johnston | United Farmers |
| Leeds | Andrew Wellington Gray | Conservative |
| Lennox | Reginald Amherst Fowler | Conservative |
| Lincoln | Thomas A. Marshall | Liberal |
| London | Hugh Allen Stevenson | Labour |
| Manitoulin | Beniah Bowman | United Farmers |
| Middlesex East | John Willard Freeborn | United Farmers |
| Middlesex North | James C. Brown | United Farmers |
| Middlesex West | John Giles Lethbridge | United Farmers |
| Muskoka | George Walter Ecclestone | Conservative |
| Niagara Falls | Charles Fletcher Swayze | Labour |
| Nipissing | Joseph Marceau | Liberal |
| Norfolk North | George David Sewell | United Farmers |
| Norfolk South | Joseph Cridland | United Farmers |
| Northumberland East | Wesley Montgomery | United Farmers |
| Northumberland West | Samuel Clarke | Liberal |
| Ontario North | John Wesley Widdifield | United Farmers |
| Ontario South | William Edmund Newton Sinclair | Liberal |
| Ottawa East | Joseph Albert Pinard | Liberal |
| Ottawa West | Hammett Pinhey Hill | Conservative |
| Oxford North | John Alexander Calder | Liberal |
| David Munroe Ross | United Farmers | |
| Oxford South | Albert Thomas Walker | United Farmers |
| Parkdale | William Herbert Price | Conservative |
| Parry Sound | Richard Reese Hall | Liberal |
| Peel | Thomas Laird Kennedy | Conservative |
| Perth North | Francis Wellington Hay | Liberal |
| Perth South | Peter Smith | United Farmers |
| Peterborough East | Ernest Nicholls McDonald | United Farmers |
| Peterborough West | Thomas Tooms | Labour |
| Port Arthur | Donald McDonald Hogarth | Conservative |
| Prescott | Gustave Évanturel | Liberal |
| Prince Edward | Nelson Parliament | Liberal |
| Rainy River | James Arthur Mathieu | Conservative-Liberal |
| Renfrew North | Ralph Melville Warren | United Farmers |
| Renfrew South | John Carty | United Farmers |
| Riverdale | Joseph McNamara | Soldier |
| Russell | Damase Racine | Liberal |
| Alfred Goulet | Liberal | |
| Sault Ste. Marie | James Bertram Cunningham | Labour |
| Simcoe Centre | Gilbert Hugh Murdoch | United Farmers |
| Simcoe East | John Benjamin Johnston | United Farmers |
| Simcoe South | Edgar James Evan | United Farmers |
| Simcoe West | William Torrance Allen | Conservative |
| St. Catharines | Frank Howard Greenlaw | Labour |
| Stormont | James William McLeod | Liberal |
| Sturgeon Falls | Zotique Mageau | Liberal |
| Sudbury | Charles McCrea | Conservative |
| Timiskaming | Thomas Magladery | Conservative |
| Toronto Northeast - A | Henry John Cody | Conservative |
| Alexander Cameron Lewis | Conservative | |
| Toronto Northeast - B | Joseph Elijah Thompson | Conservative |
| Toronto Northwest - A | Thomas Crawford | Conservative |
| Toronto Northwest - B | Henry Sloane Cooper | Liberal |
| Toronto Southeast - A | John O'Neill | Liberal |
| John Allister Currie | Conservative | |
| Toronto Southeast - B | James Walter Curry | Liberal |
| Toronto Southwest - A | Herbert Hartley Dewart | Liberal |
| Toronto Southwest - B | John Carman Ramsden | Liberal |
| Victoria North | Edgar Watson | United Farmers |
| Victoria South | Frederick George Sandy | United Farmers |
| Waterloo North | Nicholas Asmussen | Independent Liberal |
| Waterloo South | Karl Kenneth Homuth | Labour-United Farmers |
| Welland | Robert Cooper | Liberal |
| Wellington East | Albert Hellyer | United Farmers |
| William Edgar Raney | United Farmers | |
| Wellington South | Caleb Henry Buckland | Conservative |
| Wellington West | Robert Neil McArthur | United Farmers |
| Wentworth North | Frank Campbell Biggs | United Farmers |
| Wentworth South | Wilson A. Crockett | United Farmers |
| Windsor | James Craig Tolmie | Liberal |
| York East | George Stewart Henry | Conservative |
| York North | Thomas Herbert Lennox | Conservative |
| York West | Forbes Godfrey | Conservative |