Early political career Stiles served as a trustee for the
Toronto District School Board from 2014 until 2018, for ward 9.
Provincial politics in the
Legislative Assembly of Ontario, 2019 Contesting Davenport for the provincial NDP in the
2018 Ontario election, Stiles ran against
Liberal incumbent
Cristina Martins, who faced criticism for her government's handling of the Davenport Diamond rail overpass. Stiles campaigned for the electrification of the nearby
GO Transit line and ensuring all “amenities” associated with the Davenport Diamond rail bridge are completed. She defeated Martins, becoming the riding's second NDP MPP. Stiles was the party's education critic from 2018 to 2022.
Leader of the Ontario NDP Following the
2022 provincial election, the NDP remained in opposition and party leader
Andrea Horwath stepped down. MPP
Peter Tabuns became interim leader until the party could hold a
leadership election in 2023. Stiles announced that she would run for NDP leader on September 22, 2022. During her campaign, she received endorsements from eight fellow MPPs. She called for "true reconciliation" by protecting
indigenous rights and addressing issues such as clean drinking water, treatment in the justice system and shelter. While several other MPPs had explored running for leader, none were able to meet the entry requirements—which included raising a $55,000 fee—before the December 5 deadline. Premier Doug Ford congratulated Stiles in a brief statement posted to Twitter stating "I'm looking forward to many spirited debates as we both strive to make Ontario the best place to live, work and raise a family." Stiles was formally confirmed on February 4, 2023, taking office as leader of the NDP and becoming the
leader of the Official Opposition in Ontario. event in Cambridge, Ontario, July 2024 In October 2023,
Hamilton Centre MPP
Sarah Jama was removed from the NDP caucus for allegedly failing to abide by the terms of an agreement between herself and Stiles. Jama was accused of taking a "number of unilateral actions" without party endorsement, which included making statements regarding the
Gaza war; being uncooperative with NDP colleagues; and threatening
Premier Doug Ford with legal action without first consulting her caucus. Stiles had originally defended Jama, and had met privately with Jama beforehand, asking her to remove her statement and apologize. Jama subsequently apologized for her posts but, in defiance of the party's directive, refused to remove the statement, instead pinning it to the top of her feed on X. Jama said: "I don't plan on apologizing..." The NDP was divided over the issue. Some in the NDP stated that Jama should have been ejected sooner for refusing to remove her statement; some were critical of the political damage that resulted from the delay in expelling Jama with one MPP having to be convinced not to quit the NDP over the delay; while others criticized Stiles for her decision to remove Jama from caucus including two constituency associations that demanded Stiles resign as leader. In January 2025, Jama was initially told she would be allowed to run for the NDP nomination in her riding, but then was barred by the party and forced to run as an independent. She led the party into the snap
2025 Ontario general election, winning 27 seats and forming the Official Opposition for the third consecutive time, a first in party history. However, the party's vote share slipped below 20 per cent. Following the election, Stiles began a tour of the province during the summer months of 2025. On September 20, 2025, Stiles received 68 percent support in a leadership review vote during the party's provincial convention. On November 19, 2025, Stiles was ejected from the
Legislative Assembly during question period, after she described
Doug Ford's government as "corrupt," while criticizing them for the Skills Development Fund scandal. In January 2026,
Scarborough Southwest MPP and the party's deputy leader
Doly Begum resigned her seat to run for the federal
Liberals in a
by-election. == Personal life ==