Francis presided over the ceremony, which took place at St. Peter’s Basilica. Benedict’s surprise appearance was his first at a papal rite since his resignation last year.
Lacroix, who hails from Saint-Hilaire-de-Dorset, was named a cardinal by Francis on January 12.
Saturday's ceremony saw Lacroix receive his three-cornered biretta hat and cardinal's ring of office.
Ordained in 1988, Lacroix was elevated to Archbishop of Quebec in 2011 to replace Marc Ouellet. He also became Primate of Canada at the same time.
As a cardinal, Lacroix, 56, will be able to enter a conclave to elect a pope. Cardinals are the pope’s closest advisors and help make church policy.
Lacroix's appointment brings the number of Canadian cardinals serving the pope to four. The other three are Marc Ouellet, Jean-Claude Turcotte and Thomas Collins.
The other newly inducted cardinals hail from countries including Italy, Germany, Britain, Nicaragua, Ivory Coast, Brazil, Argentina, South Korea, Chile, Burkina Faso, the Philippines and Haiti.
The selections indicate the importance Francis attaches to the developing world. Francis is the first Latin American pope and the first non-European pontiff in some 1,300 years.