"Almost 50 lbs off - I can see it now," the 52-year-old comedian captioned the pic.
While speaking at the American Heart Association in February, O'Donnell revealed that she had lost 40 pounds thanks to a weight-loss surgery. She said she went from 230 pounds to 190 and explained that the heart attack she suffered in August 2012 prompted her to get the surgery.
"I did it to save my life," she said.
O'Donnell currently stars in the ABC Family show The Fosters and is set to appear on the The View alongside other former hosts to send off Barbara Walters as she exits the show on May 15.