The fourth and final season of The O.C., an American teen drama television series, aired in the United States from November 2, 2006, to February 22, 2007, and consisted of 16 episodes.

would attract back viewers it had lost since the end of the previous season; however, the move was unsuccessful and the show returned to its Thursday timeslot.

[8] In the United Kingdom the season premiered on January 9, 2007, on E4,[9] and in Australia it was broadcast by Network Ten on November 7, 2006, at 8:30 p.m. (local time).

[27] The executive producers were Bob DeLaurentis, creator Josh Schwartz and Wonderland co-founders McG and Stephanie Savage.

Rachel Bilson as Summer, Adam Brody as Seth, Melinda Clarke as Julie, Peter Gallagher as Sandy, Benjamin McKenzie as Ryan, and Kelly Rowan as Kirsten all returned to the main cast.

[27] Former main cast member Mischa Barton did not return because her character, Marissa, died in the third season finale.

[30] Autumn Reeser as recent high school graduate Taylor Townsend, and Willa Holland as Marissa's younger sister Kaitlin both joined the main cast, having previously held recurring roles.

Other cast members returning in recurring roles include Cam Gigandet as Volchok,[31] Erin Foster as Heather, Michael Nouri as Summer's father Dr. Neil Roberts,[32] Paula Trickey as Taylor's mother Veronica, and Ashley Hartman who starred as Holly Fischer in the first season.

New members who joined the cast include Kevin Sorbo as Ryan's father Frank;[34] Gary Grubbs as an oil merchant who calls himself The Bullit;[35] Brandon Quinn as Bullit's son Spencer; Chris Pratt as an environmental activist nicknamed Che;[36] and Wayne Dalglish and Corey Price as Luke Ward's younger twin brothers Brad and Eric.

[37] New guest stars who joined in recurring roles include Tia Carrere as Dean Torres,[38] singer Chris Brown as lonely band geek Will Tutt,[36] Henri Lubatti as Taylor's ex-husband Henri-Michel de Momourant,[32] and Steve-O in a cameo role as an unnamed marine.

He added that "the scripts are snappy, the plots make sense, the acting's solid, [and] the music is appropriately indie" but criticized Fox for "throwing away" the show by giving it the Thursday 9:00 p.m.

"[52] Belinda Acosta of The Austin Chronicle agreed praising the show's "new energy" and its ability to successfully cover "the transition between high school and college that other series have stumbled over".

[53] Entertainment Weekly's Ken Tucker commented that the fourth season was "a succession of terrific subplots" and praised new main cast member Taylor "as a fine, funny love interest for Ryan".

As well as every episode from the season, the DVD release features bonus material including unaired scenes, featurettes, and audio commentary on the series finale.