The 43-year-old British DJ and producer recalled the incident during Thursday's episode of Watch What Happens Live.
Ronson DJed Cruise and Holmes' wedding at Odescalchi Castle in Bracciano, Italy, in 2006. Brooke Shields, Will Smith and Jada Pinkett Smith, John Travolta and Kelly Preston, David Beckham and Victoria Beckham, and Jennifer Lopez were among the guests in attendance, but Ronson said he was most starstruck by Cruise.
"I got really drunk," Ronson told host Andy Cohen, "and something about when I'm DJing, I don't realize I'm drunk so I keep drinking and then the minute the music stopped I started spinning. So I threw up all over the castle."
"I got outside the castle but it was like, we got in the car for three minutes. It was in the Italian countryside. It was very disrespectful. I'm sorry, Tom," he said.
Ronson said he mixed Top Gun-themed songs during his DJ set.
"It was an amazing wedding," he said. "I was mixing Top Gun-themed things and he was shooting the [finger] guns at me. It was cool."
"They're both such great actors and performers, and they really did perform that song so well together. I thought it was one of the great performances. I know that song and I was still kind of moved by it," the DJ said. "It was really great."
"He has everything to lose," he added of Cooper singing. "That was so brave of him to get up -- that's the only time he's going to sing in front of people -- he got up there and killed it. I just that that was so cool."
Ronson, the stepson of Foreigner guitarist Mick Jones, has produced songs for Amy Winehouse, Christina Aguilera, Lay Gaga and Miley Cyrus. He will release his fifth studio album, Late Night Feelings, on June 21.