"I can't wait to marry Howard," she told Newsday before the ceremony at Manhattan's tony Le Cirque restaurant, adding, "I know, everyone laughs!"
The bride wore a white chiffon gown with cutaway back and sides.
Officiating at the ceremony was actor Mark Consuelos, Kelly Ripa's husband and an ordained minister.
The 180 guests included Joan Rivers, Barbara Walters, Billy Joel, Steve Schirripa, Chevy Chase, Tommy Mottola, and Donald and Melania Trump.
They dined on tuna tataki, scrambled eggs with white truffles and striped bass with caviar - washed down with wine and champagne.
Songwriter Phoebe Snow serenaded the newlyweds with "You Send Me," and Joel crooned "The Stranger."
The wedding is an about-face for the media maverick, who once worried on the air that marriage to the model could spoil a good thing.
"It's a nice feeling that we get along great," he said in 2006. "We're very happy, and I don't want to (blank) it up."
But he took the plunge anyway.
Stern told listeners he surprised Ostrosky with an engagement ring in February 2007 - while they were naked in bed.
During his first marriage, he boasted of his fidelity while hosting strippers and porn stars on his show.
Stern and his wife of 21 years, Alison Berns, had three daughters before divorcing in 2001. Their romance inspired his film "Private Parts."
