The show's producers say the first lady will tape an appearance Wednesday to discuss new provisions of her "Let's Move!" campaign and the Presidential Youth Fitness Program.
Producers said Thursday that Mrs. Obama's appearance will be taped at the show's New York studio for national broadcast Sept. 14.
The show's host, Mehmet Oz, says he's "honored" that she has chosen to be a guest on his show.
"The Dr. Oz Show," which airs weekdays in syndication, starts its fourth season next month.
The first lady also will appear on the CBS "Rachael Ray" season-seven premiere Sept. 17, and discuss health and fitness.