Turcotte, 78, was hospitalized last summer, Christian Lepine said in a statement.
"Despite the high-quality care he received and the devotion of his loved ones, his health continued to deteriorate until he was admitted to a palliative care unit on March 24 (Tuesday)," the statement read.
Turcotte was archbishop of Montreal for 22 years and was appointed a cardinal in 1994.
"Let us entrust Cardinal Jean-Claude Turcotte to Jesus, our risen Lord," Lepine said.
Turcotte retired as archbishop in 2012.
Turcotte was named to the Order of Canada, but renounced the honour in 2008 in protest because anti-abortion crusader Dr. Henry Morgentaler was named to the order.