what year in highschool are the boys in the OC in the the first season?

Answer 1

I don't believe it's ever specified on the show. All of the actors, of course, were in their 20's and old enough to be out of high school in the first season (except for Marissa, who was 17). But the characters don't graduate high school until the last episode of the third season, so if they're in real-time, that would mean that they were in 10th grade when it started.