The award was presented to Jean in Paris by Gen. Jean-Louis Georgelin, the grand chancellor of the Legion of Honour.
The Legion of Honour, established by Napoleon Bonaparte in 1802, is given out to recognize "outstanding merits" in the service of France.
Jean said she is "deeply moved" by the honour.
In giving her the award, Georgelin said Jean's life had been marked by achievement.
Born in Port-au-Prince, Haiti, in 1957, Jean immigrated to Canada with her parents in 1967.
She was a successful journalist for 18 years before being named Governor General of Canada in 2005.
Upon completion of her mandate in 2010, she joined UNESCO as special envoy to Haiti.
Georgelin said her life "has been marked by values and commitments that France only can salute."
"You care profoundly about human rights and you have been defending those rights for more than 30 years."
In accepting the award on Thursday, Jean recalled other Canadians who received it, such as Quebec premier Louis-Alexandre Taschereau, governor general Georges Vanier, and prime minister McKenzie King.
"All have now passed away," she said. "I, for one, am still very much alive and well. You are giving me wings! In all humility, it is now my turn to thank France."Suggest a correction