Jeff Trammell, the former rector of the College of William and Mary in Williamsburg, Va., told BuzzFeed the ceremony Tuesday in the lawyer's lounge at the Supreme Court Building in Washington was "very traditional."
"It was wonderful," Trammell said. "It was everything you'd expect it to be: elegant, charming, very moving. She really was wonderful, in private just like she is in public."
O'Connor is the second current or former justice to marry a gay couple. Ruth Bader Ginsburg presided at a same-sex ceremony soon after the court struck down the Defense of Marriage Act.
Trammell said he got to know O'Connor when he became rector of William and Mary, where she was the chancellor. He currently heads his own political consulting firm in Washington.
Trammell and Stuart Serkin have been together for more than three decades.
O'Connor, who retired from the court in 2006, was appointed by President Ronald Reagan. She became known on the court as an independent.