Caleb was one of the wealthiest people in Newport Beach, owning the property and real estate company Newport Group which owns a substantial amount of property in Newport which contributed to the idea that he "owned" Newport. He was portrayed as a powerful and influential businessman who was known for dishonest business dealings and practice. He also was somewhat controlling and manipulative, shown perhaps by the way he treated his daughter Kirsten who worked for him. He did appear however to genuinely care for his children and was something of a prominent social figure. His relationship with his son in law, Sandy Cohen, is mixed, being particularly bad and resentful to being somewhat of a mutual understanding when Sandy helped Caleb with his legal troubles.
Caleb married Julie Cooper at the end of season one in a uneventful wedding ceremony. Many suspected it was for social and financial gain for both parties concerned, and proved to be a troubled marriage. He confessed that the Newport Group was in deep financial debt.
A long kept secret of an illegitimate child, Lindsay Gardner came back to haunt him. He attempted to build a relationship with her at the start and at one point was intent on adopting her, but this relationship collapsed when he caved into Julie's demands for a blood test. The blood test confirmed Lindsay was Caleb's daughter, but Lindsay left with her mother shortly after. Caleb also developed a heart condition after having a confrontation with Ryan Atwood about Ryan's interference with his relationship with Lindsay. He also eventually ended his troubled marriage with Julie when he found out she had been having an affair with a man from her past called Lance Baldwin, who released a pornographic video tape of Julie, humiliating both Caleb and her. Julie originally intended to kill him with poison after she found out she would not get anything from the divorce settlement as a result of not having been married to him for a year. However at the last minute she backed out but instead Caleb suffered a fatal heart attack. It was later revealed that he was bankrupt, with massive company debts in the Newport Group and high interest loans and mortgages, leaving neither Julie nor Kirsten with anything.
- Caleb Nichol: It'll get you back to your Berkeley days. Maybe you can smoke the tree. - The Best Chrismukkah Ever
- Caleb Nichol Peter Munch smell. - The Best Chrismukkah Ever
- Caleb Nichol: In the intro it's "here we go" not come.
- Caleb: Do you hear a clicking on the phone? Every time I try to dial out I swear I hear a clicking.
- Julie: Okay, Nixon. Paranoid, much? What's going on with you, Cal? You're either hopped up on blow or something's seriously wrong. - The Distance
- Caleb: I'm going to bed. The pleasure is all yours, Sanford. Enjoy. - The Way We Were
- Caleb: No, I'm not dragging Sany into anything. Before he put these eggs in front of me he was the closest thing I had to a friend in this town. - The Way We Were
- Caleb: When I have champagne I get giggly. - The New Kids on the Block
- Sandy: Facing Kirsten and Julie has got to be better than going to jail.
- Caleb: Kirsten maybe. Not Julie. - The Chrismukkah That Almost Wasn't
- Caleb: I'm sorry, Ryan. I know it wasn't easy for you to string so many words together. - The Lonely Hearts Club
- Caleb: What is this? The Color of Money? - The Lonely Hearts Club
- Caleb: What's all this?
- Julie: What does it look like?
- Caleb: It looks like one of your movies.
- Julie: That's not funny.
- Caleb: It's not supposed to be. - The O.C. Confidential
- Caleb: You spent two hours making Eggs Benedict for a man with a heart condition. Doesn't that seem a little insane to you? - The Showdown
- Caleb: You have been monitored to one degree or another since before we were married. The affair you had with your former-husband. The tryst with that high-schooler... Luke.
- Julie: Oh my god.
- Caleb: I mean, your daughter's boyfriend. What will people think?
- Julie: Ex-boyfriend. - The Showdown
- Caleb: I see you're employing your usual soft ball approach. That might be appropriate when your son runs off to Portland, but this is a tad more serious. - The O.Sea
- Caleb: You know, I really did love you, Ju-Ju.
- Julie: Ooh. Past tense. That stings.
- Caleb: Sorry. Grammatical error. - The O.Sea
- The Girlfriend
- The Perfect Couple
- The Homecoming
- The Best Chrismukkah Ever
- The Links
- The Rivals
- The Truth
- The Heartbreak
- The Telenovela
- The Goodbye Girl
- The L.A.
- The Proposal
- The Shower
- The Strip
- The Ties That Bind
- The Way We Were
- The New Kids on the Block
- The New Era
- The Chrismukkah That Almost Wasn't
- The Power of Love
- The Ex-Factor
- The Accomplice
- The Second Chance
- The Lonely Hearts Club
- The Test
- The Rainy Day Women
- The Mallpisode
- The Blaze of Glory
- The Brothers Grim
- The O.C. Confidential
- The Showdown
- The O.Sea