The Women's Post publisher arrived at city hall by horse and carriage on Thursday and filled out nomination papers at the clerk's office to officially to register as a candidate.
Thomson ran for mayor in 2010 before dropping out of the race. At the time she stated that a lack of funds force her to withdraw. She also ran provincially for the Liberals in 2011, losing to NDP incumbent Rosario Marchese.
Thomson told reporters she travelled to city hall by horse and buggy as a reminder that Toronto needs new investments in transit.
Thomson also said that this time, she plans to remain in the race until the Oct. 27 vote.
Thomson made headlines last spring when she accused Mayor Rob Ford of groping her at a party and making a suggestive comment about her. Ford has denied the allegations.
Thomson joins a crowded field of candidates that already includes:
- Former NDP MP Olivia Chow.
- Former councillor David Soknacki.
- Former Ontario Progressive Conservative leader John Tory.
- Former TTC Chair Karen Stintz.