The 39-year-old actress and her partner Jason Bleick welcomed son Arthur Saint Bleick into the world yesterday (25.07.11) - 18 days past her due date - her representative has confirmed.
The baby weighed in at 7lbs 12oz.
Selma announced her pregnancy in January, but refused to reveal whether she knew the gender of the baby.
She said only: "I`m not going to say what it is yet. Hopefully, it`s one or the other."
Prior to meeting clothing designer Jason 18 months ago, the brunette beauty - who was married to musician Ahmet Zappa for two years - admitted while she was enjoying spending time with her girlfriends, she was still on the lookout for someone who made her feel good about herself.
She said: "I`ve just been reconnecting with my friends. I want someone who makes me feel good, if you know what I mean!"
However, Selma - who has been spotted wearing a ring on her engagement finger in recent weeks - admitted she had "little faith" she`d ever find her soulmate.
She explained: "I have very little faith that I`ll ever find someone. I`ve had some bad luck and I`ve made some bad choices - not in men, but in how I`ve chosen to deal with relationships."