The 50-year-old actor is said to be smitten with ambitious Irish beautician Cathriona White, who he has been seeing for the past month, and insiders say she is hoping his celebrity status can help her with her career.
A source told RadarOnline: "Jim and Cathriona have been dating for over a month now.
"She comes from a very small rural village in County Tipperary and left Ireland for Los Angeles after studying to be a beautician. "Cathriona is ambitious and is working as a make-upartist in Hollywood - and she`s already worked on many film sets since arriving in the States.
"She`s very focused on making this work and will do anything she can to make sure she`s successful.`
"And dating Jim certainly can`t hurt her career. His status will certainly give her a leg up in the industry and open doors for her that could have been more difficult if she didn`t know him. "She`s definitely living in a dream world right now."
Jim was previously married to waitress Melissa Womer from 1987 to 1995 and his `Dumb and Dumber` co-star Lauren Holly from 1996 to 1997, and to actress.
He split from long-term girlfriend Jenny McCarthy in 2010.