Gillian Anderson at premiere in London
10/20/2008 at 07:35 PM EDT
star Gillian Anderson and boyfriend Mark Griffiths are parents of a baby boy, the actress's rep tells PEOPLE exclusively.
Felix Griffiths, weighing 6 lbs., 15 oz., was born Oct. 15 in London, says rep Kelly Bush.
Felix is the second child for Anderson, 40, with Griffiths, joining their 1-year-old son Oscar. Anderson also has a 14-year-old daughter, Piper, from a previous marriage.
To keep track of upcoming celebrity baby arrivals, visit Celebrity Baby Blog's Who's Due Next Gallery