People magazine reported online Saturday that Carrey, 47, confirmed via Twitter the birth of Jackson Riley Santana on Friday. The infant reportedly weighs 7 pounds, 11 ounces and is 20 inches long.
Carrey's 22-year-old daughter said in 2009 she was looking forward to having a son with her husband, Alex Santana.
"I'm excited about it because I never really got along with girls growing up," the younger Carrey said. "I was a little afraid that if it was a girl that she would not like me, you know? So I'm very happy about the boy."
Jim Carrey was equally excited last July about the impending birth, saying his daughter was ready to become a parent.
"Jane is going to be a great mom," said Carrey, whose films include "How the Grinch Stole Christmas" and "Bruce Almighty."