He was taken to hospital in Orillia, Ont., Saturday and airlifted to McMaster University Medical Centre in Hamilton early Sunday, hospital officials said.
Lightfoot, 63, had been in his hometown Orillia for a concert to promote his latest album, A Painter Passing Through.
CBC ARCHIVES: Gordon Lightfoot
Gordon Lightfoot in 2000
The concert at the Opera House was cancelled because the folk-rock icon was suffering stomach pains.
Rick Haynes, a longtime friend and bass player in Lightfoot's band, told reporters the singer is in intensive care, but he's conscious and making progress.
"He's feeling much better. He's not in as much pain as he was in yesterday," Haynes said.
"This family really appreciates everybody's concern, but they ask for some privacy and some time to collect themselves."
Haynes said Lightfoot is being cared for by doctors who specialize in gastrointestinal problems.
Lightfoot rose to fame in the 1960s folk music heyday, and later made a successful transition to pop music.
His hits include the classics The Canadian Railroad Trilogy and Wreck of the Edmund Fitzgerald.
He has a star on the Canadian Walk of Fame, and a place in the Canadian Country Music Hall of Fame. Among his many accolades, Lightfoot has been nominated five times for Grammy awards and has won 17 Junos.
Lightfoot was named to the Order of Canada in 1970 in recognition of his contributions to Canadian culture.
