Cayden Wyatt Costner was born on Sunday evening at a Los Angeles hospital. A spokesperson for the 52 year-old star confirmed the news, saying, "Both mother and son are doing well."
It is the first child for Costner and Christine Baumgartner, 33, who were married in September of 2004.
The star of the films Dances with Wolves, The Untouchables and JFK, among others, was previously married before.