Also celebrating birthdays today are Freida Pinto, Ne-Yo, Gabriel Sunday and Carly Shroeder.
In honor of Zac's birthday, we've listed our 5 favorite characters that Zac has played. Do you agree or disagree?
1. Cameron - "Summerland" - Sorry Troy Bolton, but Zac first won our hearts opposite Jesse McCartney on the short-lived WB series. Who didn't love that gap in his front teeth?
2. Troy Bolton - "High School Musical" - If you're ever having a bad day and need to smile, just play the musical scene for "Bet On It" from HSM2. It's bound to make you laugh.
3. Stephen Morgan - "Miracle Run" - Zac made us laugh and cry with his heartfelt performance as the autistic son of Mary Louise Parker in this Lifetime movie. Zac played opposite his real life best friend Bubba Lewis.
4. Link Larkin - "Hairspray" - Who knew Zac made such a good crooner?! With that smile, that hair, those blue eyes...ok we'll stop now.
5. Mike O'Donnell - "17 Again" - How could you resist him during that slow-mo scene in the high school parking lot when he puts on that leather jacket.
Happy birthday to everyone celebrating today!