The Lost alum, 44, first revealed his baby news in an interview with Entertainment Tonight, when he was asked what it's like to be a TV sex symbol.
"That's funny because I'm a family man," the Intelligence actor told ET. "I've got a four-and-a-half-year-old daughter and another one on the way. Pretty excited about that."
Holloway proposed to his wife after shooting the pilot of Lost in Hawaii; they married in October 2004. A little less than five years later, in April 2009, they welcomed their first child, daughter Java.