The 40-year-old blonde beauty was accompanied by her new boyfriend on double date with her good friend Drew Barrymore and her husband Will Kopelman recently, reported Contactmusic.
Diaz has been spotted enjoying a cosy dinner with a dapper gentleman dressed in a suit at a posh restaurant.
"The couples appeared to be having a great time together ... Although Cameron introduced her guest to Drew, who gave birth to her first child Olive last October.
"Drew was raving about her baby and the best friends appeared to be having a great time," a source said.
Diaz has previously dated several famous men, including singer-actor Justin Timberlake, baseball player Alex Rodriguez and actor Jared Leto.