The 23-year-old singer admitted as much in a joint interview with Jonas for Billboard, explaining she didn't think the couple were right for each other.
"He's a guy in his 20s and he's famous and he likes to have a lot of fun," Lovato said. "When he was in a relationship, I was like, 'Get out of that. You could [expletive] anybody that you want right now, so have fun and do that.'"
"[When they split I said], 'Honestly, I didn't like her anyway,'" she revealed. "It's not because she's mean or anything, but he has such a great sense of humor and I want him to be with someone that makes him laugh."
Jonas and Culpo, the 24-year-old Miss USA 2012 winner, called it quits in June 2015 after nearly two years of dating. Entertainment Tonight reported at the time that the split left Culpo "heartbroken."
"She's an amazing person," Jonas told Extra after the breakup. "We had a great, a beautiful two years together. It's been a crazy couple months and I wish the best for her in the future. It is tough, though."
Lovato and Jonas are both single but told Billboard they will "never" be romantic. Lovato split from actor Wilmer Valderrama in June after six years of dating, while Jonas was last linked to actress Kate Hudson.