Assefa, a handbag designer, gave birth Monday to a boy at the Cedars-Sinai Medical Center, People magazine reported Thursday.
"Wolfgang and Gelila are overjoyed to welcome to their family ... Alexander Wolfgang Puck," said Clare Davis, acting as Puck's representative, of Wolfgang Puck Catering.
Alexander is the second son for Puck, 57, and Assefa, 37. Their other son, Oliver, was born in July 2005. Puck has two sons from his first marriage to business partner Barbara Lazaroff as well.
Puck owns the new Beverly Hills steakhouse Cut at the Beverly Wilshire Hotel as well as many other restaurants around the world.