Ashley Tisdale celebrated her birthday last week and fans were shocked to find out that the High School Musical star turned 30. It wasn't too long ago that she was playing a high school student on the Disney Channel!
Ashley's not the only celebrity you'd be shocked to know is in her 30s. A bunch of stars (even ones who play high schoolers on TV and in movies) are way older than you realized!
Click through the gallery to see 10 stars who are in their 30s, then let us know in the comments below who you're the most shocked to see on the list.