The country marks the signing on the British North America Act in 1867, which united the British provinces of New Brunswick, Nova Scotia, Quebec and Ontario into the Dominion of Canada.
Originally called Dominion Day, the holiday was renamed in 1982 and has gone on to imbue a sense of nationalism and pride.
Not everyone sees the logic in spending US$54,000 (£40,000) on the float, which incidentally is being rented from an American company.
Despite the criticism, the giant duck is not expected to cast a shadow on the festivities.
In Ottawa, the Parliament Hill show is expected to be packed with celebrity performances by U2's Bono and The Edge, Gordon Lightfoot, Alessia Cara and Cirque du Soleil.