* ActorAllusion: At Kaitlin's school, Marissa pretends to be an exchange student from London. Mischa Barton was born in London to British parents. OohMeAccentsSlipping also applies and is lampshaded.
* BillingDisplacement: Peter Gallagher & Kelly Rowan are billed first in the opening credits for all 4 seasons, despite their characters being less prominent than the teenagers. When Melissa Clark & Rachel Bilson were added as regulars, Clark was again billed ahead of Bilson despite the same applying.
* CreatorBacklash:
** Mischa Barton publicly blamed the show for her personal issues. Shortly after the show'a cancellation, she said it was no surprise the show had been cancelled, since they killed her off.
** Tate Donovan has been rather critical of the show's younger actors in interviews following his departure from the show.
* CreatorBreakdown - Josh Schwartz was jaded by pressure from some fans and ExecutiveMeddling and seemingly zoned out during Season 3.
* DawsonCasting:
** Benjamin Mackenzie, Adam Brody, Rachel Bilson & Autumn Reeser were all in their early to mid twenties playing teenagers. Lampshaded in "The L.A."
-->'''Ryan''' (speaking of the star from the ShowWithinAShow): How does that guy play high school?\\
'''Seth''': It's ''Hollywood'', man.
** Averted with the Coopers. Mischa Barton was 17 playing 16 and Willa Holland was 14 playing 14.
* {{Defictionalization}}: Before the series, "OC" was sometimes used in print as shorthand for "Orange County," but very rarely in speech, and never prefixed with a "the." Many Orange County residents scoffed at the show's title, but over the years, some of them really do refer to the region "the OC" without irony.
* DuelingShows: With Series/OneTreeHill. The latter lasted longer, but The OC is usually thought to be the better of the two.
* ExecutiveMeddling - Resulted in the end of the Marissa/Alex lesbian relationship. Also, apparently a big factor for the quality decline in Season 3, as Fox wanted something 'promotable' to happen every week. The writers once got a note that said, "This is Fox, not Fox Searchlight".
* FakeAmerican[=/=]FakeNationality: Kelly Rowan is Canadian.
* McLeaned: [[spoiler:Marissa Cooper]] was killed off at the end of season 3, as the actor wanted off the show.
* TheOtherDarrin:
** Willa Holland replaced Shailene Woodley as Kaitlin Cooper; lampshaded when Ryan didn't recognize her after she returned.
** Trey Atwood.
** Theresa's mother.
* ThePeteBest: Shailene Woodley is not as remembered in the role of Kaitlin Cooper as her replacement, Willa Holland.
* PlayingGertrude: Amanda Righetti was 20 playing 25 year old Hailey Nichol. This also resulted in her being younger than Adam Brody, who was playing her teenaged nephew.
* RomanceOnTheSet: Adam Brody and Rachel Bilson were engaged in real life.
* StarMakingRole: For Rachel Bilson; to a lesser degree for Benjamin [=McKenzie=] & Autumn Reeser. For Willa Holland.
* WhatCouldHaveBeen:
** Kaitlin was reintroduced in season 3 with a view to creating a spin-off following Kaitlin & her friends at boarding school. This was then retooled into keeping Kaitlin as a main cast member in the fourth season so they could keep the high school drama aspect of the show after the original group had graduated.
** The writers tried to get Trey to return in Season 4 to finish his story arc.
** In the same season, UsefulNotes/AlGore was supposed to be Summer's GEORGE recruiter, but had scheduling differences.
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