Taylor Swift Once Said Diddy Would Be Great for a Group Prom Date

Taylor Swift's new album is coming out October 3, the same day Diddy is set to be sentenced in his federal criminal case ... which is interesting, 'cause T-Swift once said she'd go to prom with the guy in a group!

A clip from a 2011 interview from "The Rachael Ray Show" has resurfaced in the aftermath of Swift revealing her album release date, where Taylor selects her ideal prom date from a choice of a group of celebs.

Taylor says she'd rather go with a group than a specific date ... picking up photos of Jennifer Lopez, Justin Timberlake, Katy Perry, Sheryl Crow -- and, finally, Diddy.

Diddy's always been nice to her and he'd be super fun as part of the group date, Taylor says ... and, Ray agrees -- calling the guy a "gentleman."

Diddy had a ton of celebrity pals at the time -- but, the comment will certainly raise some eyebrows given everything that came out during Diddy's trial. Of course, you can't fault Taylor at all ... It's an innocuous quote and, at the time, she and everyone else had no idea what would eventually come out about Diddy.

As you know ... Diddy was found guilty of two Mann Act violations -- but, he was acquitted on more serious charges of sex trafficking and racketeering.

He's still in jail awaiting sentencing ... which is scheduled for Oct. 3 -- the same day Taylor's 12th studio album "The Life of a Showgirl." Taylor revealed the 10/3 release on her man Travis Kelce and his brother Jason's "New Heights" podcast.

She revealed the new album cover, settled the debate on whether she was in "Happy Gilmore 2," and shared an update about her dad, Scott, after his recent heart surgery during her appearance, too.