The actor is now legal to do just about anything a person can do anywhere in the world: drink, drive (not at the same time obvs), vote, even hire a car on his holidays!
He's come a long way from his humble beginnings as sports stud-cum-musical star in 2006 breakout hit High School Musical, where he met longtime girlfriend Vanessa Hudgens.
Gone are the questionable mop and scruffy Vans, which have been replaced by a perfectly quaffed 'do and a fine collection of suits as modelled by Zac on the red carpets for movies including The Lucky One and Charlie St. Cloud.
If you need any more convincing that it's no longer a source of shame to watch 17 Again on repeat for the bit where he plays basketball in a sleeveless shirt, comfort yourself with the knowledge that, at 25, he is seven years older than Harry Styles - 'nuff said.
Happy Birthday Zac! We don't know how you're celebrating but if you need someone to share some cake with, call us!
How would you wish Mr Efron a "Happy Birthday"? Let us know in the comments below and you could win £50!
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