Let's make this birthday one to remember.

44 years old (Born on December 22, 1980)

Happy Birthday, Chris Carmack! From your unforgettable days as Luke Ward on "The O.C."—where you taught us all that even the coolest guys can have hilariously awkward moments—to charming audiences with your soulful tunes and heartfelt performances in "Nashville," you've truly done it all. Who knew Newport Beach drama could lead to country music stardom?

Recently, we've loved seeing you save lives (and hearts!) as Dr. Atticus Lincoln on "Grey's Anatomy." Whether you're breaking bones or mending them, one thing remains clear: nobody delivers a line—or rocks scrubs—with quite the same charisma. Here's to another year of laughter and success!