Hewitt, who co-stars with Kennedy on the TV drama "Ghost Whisperer," broke off her engagement to her longtime beau, Ross McCall, earlier this year.
"Yes, we are dating," Usmagazine.com quoted Kennedy as telling Ryan Seacrest on Seacrest's KIIS-FM radio show in Los Angeles Friday.
"Wow, I've never said that," Kennedy said. "We're more than dating. ... We're more than in love. ... We have an intense connection. ... I'm in love, and I don't care! ... Ryan, you knew off-the-air because you said I seemed different to you ... It's amazing."