The Yonge-University subway line will also be closed for signal upgrades between Union and Bloor-Yonge station.
The TTC says shuttle buses will be in service, stopping at all stations except Union.
The city is advising the public to take transit to the following events to avoid traffic delays.
The roads near St. Lawrence Market will be closed from Friday at 6:30 p.m. to Sunday at 11:59 p.m.
- Front Street from Yonge Street to Jarvis Street.
- Wellington Street from Church Street to Leader Lane.
- Church Street from Colborne Street to The Esplanade.
- Market Street from Front Street to The Esplanade (Sunday only).
Toronto Challenge Run
Wellington Street from Simcoe Street to John Street will be closed in both directions on Sunday from 8:30 to 11:30 a.m.
The city also says there will also be several road closures during the event in the area bounded by Wellington Street in the south, Spadina Avenue in the west, Wellesley Street in the north and Bay Street in the east.
Ride to Conquer Cancer
Lake Shore Boulevard will be closed from Strachan Avenue to Windemere Avenue, and Windemere Avenue from Lake Shore Boulevard to The Queensway, on Saturday from 6:30 a.m. to 10:30 a.m.
The Gardiner Expressway will remain open as an alternative route for vehicle traffic.
Portugal Day Parade
Lansdowne Avenue will be closed both directions between Bloor and College Street from 8 a.m. to 1:30 p.m. on Sunday.
Dundas West Fest
Dundas Street will be closed both directions from Lansdowne Avenue to Roxton Road on Saturday from 9 a.m. to 11:59 p.m.
Queen's Park will be closed in both directions from Bloor Street to the top end of Queen's Park Circle on Saturday at 8 p.m. to Monday at 6 a.m.
Festival on Bloor
Bloor Street will also be closed from Spadina Avenue to Bathurst Street on Sunday from 7 a.m. to 8 p.m.