Stiles served as a Toronto District School Board (TDSB) trustee in 2014 and was the president of the federal NDP from 2016 to 2018, before her election as a member of Provincial Parliament (MPP).

[1] Her parents were Americans who had moved from Pennsylvania to Newfoundland in 1967 and settled on a small organic farm outside St. John's, growing vegetables and raising goats, chickens, geese, rabbits and pigs.

[1] Her first political involvement was in 1990 when she canvassed for Evelyn Gigantes along with her future partner Jordan Berger, a childhood friend with whom she became reacquainted while attending university.

Stiles went to work for the Alliance of Canadian Cinema, Television and Radio Artists (ACTRA) in 2005, where she was the director of research, public policy and communications.

Stiles campaigned for the electrification of the nearby GO Transit line and ensuring all “amenities” associated with the Davenport Diamond rail bridge are completed.

[18] She called for "true reconciliation" by protecting indigenous rights and addressing issues such as clean drinking water, treatment in the justice system and shelter.

[18] Stiles has also criticized what she perceives as the Conservatives' efforts to increase privatization of government services, and committed to improving public education, healthcare, and social security.

[19][21][22] 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.