Ryan Atwood is a troubled teenage youth from the wrong side of the tracks in Los Angeles who finds himself on his own, after he is thrown out of his own house. He finds a place to stay in the posh home of the Cohens in the wealthy community of Newport Beach, the O.C. (Orange County), California. Ryan is accepted by the stern but compassionate Sandford "Sandy" Cohen, a lawyer who has represented Ryan in the past for his misdeeds. But Sandy's wife, Kirsten, aware of Ryan's criminal history, is wary of this new house guest.
The Cohen's son, Seth, bonds with Ryan quickly and shows him the ropes of the community -- and vice-versa with Ryan giving advice to Seth about life and love. Ryan develops a crush on Marissa Cooper, a neighbor girl who lives down the street, and he has problems with her not-so-sheltered existence in dealing with her distant father Jimmy and her weak-willed mother Julie. Also, Marissa's best friend, Summer, is oblivious to the crush that Seth has on her, while taking a liking to Ryan. And so begins a new life for Ryan, the Cohens, the Coopers, and generally everyone else in the wealthy, picturesque, secretive, turbulent community in Orange County.