Selma Blair kept her baby's gender tightly under wraps during her pregnancy, but now the secret is out!
ET has learned that Selma and her boyfriend, fashion designer Jason Bleick, welcomed a baby boy on Monday.
Their new son Arthur came into the world at a healthy 7 lbs., 12 oz.
The couple, who reportedly met while working on Jason's EVER clothing line, announced Selma's pregnancy in January. This is their first child.