The Girls Aloud star mentored the singer to victory on the 2009 series of The X Factor and insisted that she had a suspicion he was homosexual during the competition.
Asked if she knew McElderry was gay during his time on The X Factor, Cole told Attitude: "Yeah, I think I knew before he did.
"He didn't tell me. I had a chat with my boys and I just told them they could tell us whatever they wanted and I was there for them."
She continued: "I really don't know if Joe knew. I had deep conversations with Joe and he never, ever suggested it, and he never said, 'That guy's fit'.
"I think he actually said a girl was one time. But I kinda knew."
Cole's new single 'Call My Name' will be released in the UK on June 10, while her third studio album A Million Lights follows on June 18.
Watch the music video for Cheryl's 'Call My Name' below: