The comic jokingly praised Baldwin's kissing ability while speaking to reporters on Thursday (May 31).
"I get to kiss Alec Baldwin… He is [a good kisser]," Brand quipped, adding: "It is right on the mouth. It is sexy because Alec is a sexy man."
Brand went on to reveal that kissing the 30 Rock star was one of the finest moments of his career.
"I certainly don't regret [kissing Alec]," he teased. "I'd do it again if there was a sequel – or even if there wasn't."
Rock of Ages, which also stars Tom Cruise and Catherine Zeta-Jones, opens on June 15 in the US and UK.
Brand hosts this weekend's MTV Movie Awards, airing live from the Gibson Amphitheatre in Universal City, California, on Sunday, June 3, at 9pm ET/PT on MTV.
Watch a trailer for Rock of Ages below: