Scott Caan and Kacy Byxbee welcome their first child together! Credit: Steve Granitz/WireImage

Hawaii Dad-O! Scott Caan and his girlfriend Kacy Byxbee welcomed their first child together, a baby girl, a source confirms to Us Weekly. This is the first child for the Hawaii Five-O actor and his girlfriend of a couple years.

The Ocean's Thirteen alum, whose dad is legendary actor James Caan, couldn't be more excited about becoming a parent. "Scott took time off from his production work so that he could be there for the birth," the source tells Us, adding that when he returned to set, "he celebrated the baby with some cheers from the crew [and] he and [co-star] Alex O'Loughlin were smoking cigars."

Also excited for the new dad is Scott's father James. Another insider tells Us, "James is really close with him and is very excited."

Back in January 2013, Scott opened up during an appearance on Chelsea Lately, complimenting Byxbee for being such a chill girlfriend. "She should get the purple heart because I'm a complete disaster," he joked.

E! News was first to report the story.