O'Donnell was hosting the New York Women in Communication annual awards luncheon at The Waldorf-Astoria hotel in Manhattan. Murdoch, the media mogul whose holdings include the New York Post and Fox News, was presenting an award to columnist Cindy Adams.
O'Donnell's shots at Murdoch started from her opening.
"This is a celebration of women who changed the world, and no one understands why Rupert Murdoch is on the dais," she said, adding, "I mean that in the kind, loving Post-like way, sir; it's delightful to see you in person."
She turned to the audience and finished, "I was looking for numbers on his head. There aren't any."
Photos: Rosie O'Donnell
O'Donnell didn't say what Murdoch might have done to provoke her ire.
When Murdoch's turn to speak came, he just said, "Thank you, everyone, including Rosie."
Among the other presenters at the luncheon was Barbara Walters, who appears with O'Donnell on "The View."
"I would like to point out that Rosie's view is not always mine," she said. "I would like to say for the record that I am very fond of Rupert Murdoch."
The Matrix Awards honor women in communication fields. Among this year's winners were Joan Didion, Arianna Huffington and Meredith Vieira. Presenters included Martha Stewart, Sen. Hillary Rodham Clinton and Anna Deavere Smith.