Keillor suffered the stroke Sunday morning and was admitted to Saint Marys Hospital at Mayo Clinic that night, said Karl Oestreich, a Mayo spokesman.
"He is up and moving around, speaking sensibly, working at a laptop, and it's expected he'll be released on Friday," Oestreich said in a statement e-mailed to The Associated Press. "He plans to resume a normal schedule next week."
A representative for Keillor didn't immediately comment.
Keillor, 67, underwent surgery to repair a heart valve at the Mayo Clinic in 2001.
He is scheduled to open the new season of "A Prairie Home Companion" on Sept. 26 from the Fitzgerald Theater in St. Paul.
Keillor celebrated "Prairie Home's" 35th anniversary with a Fourth of July performance before some 10,000 people in Avon, a central Minnesota town that helped inspire his fictional hometown of Lake Wobegon. He performed last Friday night at the Minnesota State Fair.