Zac Efron

He was hospitalized on Friday (Aug. 2).

Long live 'Tiger Beat' and 'Bop' magazine.

It's no surprise Jennifer Aniston's hair — a.k.a. "The Rachel" — made the list.

The rumors began last April.

One student thought Jesse McCartney was Justin Bieber!

The 'High School Musical' co-stars dated for roughly four years.

From Nick Jonas to Khloe Kardashian and beyond, check out 30 surprising celebrity glow-ups over the years.

Efron plays one of the most notorious serial killers in history in the new Netflix movie.

I mean, I see the resemblance.

From Lady Gaga and Bradley Cooper to Lana Condor and Noah Centineo, these celebrity pairs have chemistry onscreen and off.