The parade starts at 1 p.m. on the corner of Guy Street and René-Lévesque Boulevard. It will head east along René-Lévesque Boulevard and wrap up at Sanguinet Street.
Quebec Premier Pauline Marois is expected to join the festivities, which will be the first time a premier has participated in the tradition dating back to 1979.
She will be joined by a record number of federal, provincial and municipal politicians, including Quebec Liberal leader Philippe Couillard, NDP Leader Tom Mulcair and Liberal Leader Justin Trudeau.
Montreal mayor Laurent Blanchard will also take part.
This year’s parade will feature floats from more than 130 organizations including sports teams, cultural and community groups, businesses, as well as other gay, lesbian, bisexual and transgender groups.
This year’s theme is “Our Flag, Our Life: Red.”
Closing ceremonies will be in Émilie-Gamelin park after the end of the parade.