December 20, 2012 09:03:51 GMT
Little William Luca Costa-Marsden was born on December 14 in Los Angeles, becoming James' third child overall.
James Marsden, 39, has welcomed his third child, a baby boy named William Luca Costa-Marsden. His ex-girlfriend, Brazilian model Rose Costa, gave birth to the bundle of joy on December 14 in Los Angeles, PEOPLE confirms the happy news.
James dated Rose briefly after he split from his wife Lisa Linde in 2011. The "30 Rock" star was no longer with Rose when rumors about her pregnancy emerged this summer. Still, he's reportedly very supportive and helped pick the name for the baby.
James is already father to 7-year-old daughter Mary James and 11-year-old son Jack Holden from his marriage with Lisa. She filed for divorce from him in October 2011 after 11 years of marriage. He then met Rose after she moved to New York to pursue modeling career.