The funeral will start at 3 p.m. ET. CBCNews.ca will carry it live.
The funeral will be held at St. James Cathedral. It will be held under tight security just blocks from Toronto's financial district, a favourite Flaherty stomping ground.
Prime Minister Stephen Harper, NDP Leader Thomas Mulcair and Liberal Leader Justin Trudeau will be joined by Governor General David Johnston and a host of other dignitaries.
Flaherty died of a suspected heart attack, less than a month after resigning from cabinet.
More than 1,000 people lined up Tuesday to pay respects to Flaherty during a visitation in Whitby.