Scott Caan is going to be a daddy!

Life & Style has learned the Hawaii Five-0 star and his girlfriend, Kacy Byxbee, are expecting a baby.

"Kacy's friend posted a photo of her very pregnant belly with the hashtag #babycaan on Instagram," a source tells Life & Style.

This will be the first child for the 37-year-old actor, whose father is Hollywood legend James Caan.

Scott and Kacy met on set of the hit CBS show.

Congratulations to the happy — and growing! — family!