"The night of May 27, 2006 in Namibia, Africa, Angelina Jolie and Brad Pitt welcomed their daughter Shiloh Nouvel Jolie-Pitt. No further information is being given," publicist Cindy Guagenti said in a statement.
No photographs were being released, she added.
The baby's arrival had been the subject of intense press speculation in recent months, compelling the superstar couple to decamp to Africa for privacy.
The actors were linked romantically shortly after appearing together in the 2005 movie "Mr. and Mrs. Smith."
Jolie, 30, is a frequent visitor to Africa and serves as goodwill ambassador for the U.N. High Commissioner for Refugees.
Jolie has two adopted children: toddler Zahara, from Ethiopia, and 4-year-old Maddox, from Cambodia.
Both had their surnames legally changed to Jolie-Pitt after Pitt announced his intentions to co-adopt the children.
Pitt and actress Jennifer Aniston divorced last fall.