So, I just rewatched 10 Things I Hate About You, which I remember really liking when I was a teen, because the cast was clearly my age. Also, the movie’s really, really great. The cast were almost all actual teens, too:
Heath Ledger was 19, which actually works as he’s meant to be a bit older than the others. Julia Stiles, Joseph Gordon-Levitt and Larisa Oleynik were all 17.
The supporting cast were a bit older – David Krumholtz was 20, Andrew Keegan was 19, Gabrielle Union was 26 and Susan May Pratt was 24.