The pop star was at the Governor General's Quebec City residence to receive the award Friday, a day before her concert at the nearby Plains of Abraham battlefield.
It was a rare appearance outside Las Vegas for the Quebec-born star, who is in the midst of a three-year stint at Caesar's Palace casino.
It was initially announced in 2008 that Dion would be elevated to the highest rank of the Order of Canada, that of Companion. She was first named to the order in 1998, at the lower rank of Member.
"Thank you for this great honour," Dion said during the ceremony.
"I'll try to be worthy by being a good Companion."
She picked up the prize during a ceremony at the Citadelle fortress with her husband-manager Rene Angelil, who has now received a medal as Member of the Order of Canada.
Dion told reporters later that she had been blessed with an "amazing career," and was touched by the "wonderful" experience whenever she returns home to a warm reception.
"We come here way too little," Dion said.
She added that she had been closely following news from Lac-Megantic and was there "in spirit," in the community devastated by a train derailment July 6. The couple reportedly gave $100,000 to humanitarian efforts in the town.
Angelil thanked his wife in an emotional speech where he said his parents would have been proud to witness the moment.
"I want to thank the life given to me — (by) the exceptional artist who was my engine, and the mother and wife who was even more exceptional who gave me wings," Angelil said.
"Thank you, Celine. I adore you."
It was a unique ceremony, in that Dion and Angelil were the only recipients and they delivered short speeches from the podium. Order of Canada ceremonies are usually group events featuring multiple recipients, who receive a few words of tribute and quietly pick up their medals.
In granting her the award, Rideau Hall lauded Dion's music and humanitarian work.
"Celine Dion is not only an extraordinary ambassador for Canada, she also represents the values we hold dear," said the citation read aloud before she accepted the prize.
"Her unique voice, infectious energy and great sensitivity contribute to her remarkable stage presence, which has won her fans from around the world. Moreover, her talent has garnered her countless national and international awards and honours.
"An incomparable artist, she is equally known for her compassion, generosity and commitment to a number of social and humanitarian causes. She is notably the national celebrity patron for Cystic Fibrosis Canada and honorary patron of the CHU Sainte-Justine. In addition, through her foundation, she also helps children in need and their families here in Canada and abroad."
According to Rideau Hall, the Companion of the Order of Canada recognizes "a lifetime of outstanding achievement and merit of the highest degree, especially in service to Canada or to humanity at large."
As for Angelil, the citation lauded his philanthropic generosity, and "determination and extraordinary flair" that propelled the careers of Quebecois singers.