Cameron Diaz dating Good Charlotte rocker

Cameron Diaz has started a new romance with tattooed Good Charlotte rocker Benji Madden, and sources say he’s already “madly in love.”

Diaz, 41, and Madden, 35, have been dating for a few weeks after being introduced by Nicole Richie, a close friend of “The Other Woman” star and wife of Benji’s twin brother, Joel Madden. The siblings just announced they have formed a new band, The Madden Brothers.

A source told Page Six, “Benji is madly in love with Cameron, but she wants to take it slow — he isn’t her usual type. He has dated a lot of Nicole’s friends in the past but Nicole really wants this one to work.”

Guitarist Benji has enjoyed a private life almost as eventful as his rock career. He perhaps has a thing for blonds and has previously dated Nicole’s former best friend Paris Hilton, as well as former Hugh Hefner girlfriend Holly Madison and Australian starlet and model Sophie Monk, to whom he was engaged until 2008.

Meanwhile, Diaz — who’s been linked to Matt Dillon, Justin Timberlake and Alex Rodriguez — recently revealed she is completely comfortable with her single status, even though it makes married people nervous.

She said earlier this year, “I think that some married people have made the choice to get married, but when they see a person who is living a different way, it makes them stop and think, ‘Wait a second — you mean you don’t need to get married after all?’ ”

But Diaz added she hasn’t given up on romance. “I’m totally down for love,” she said. “And I now know that what is most attractive in a man to me is authenticity . . . I am attracted to someone who knows who he is.”

Our source added that Benji and Cameron have been spending a lot of time at her Hollywood home, and have also been spotted working out together at an Equinox gym in Los Angeles.

A rep for Diaz didn’t get back to us, while Benji’s spokeswoman said, “I do not comment on my artists’ personal lives.”