- The series 4 episode "Negative Reaction" Columbo goes to a homeless shelter to look up a drunken witness, except the nun mistakes him for a homeless person while being very sweet and genuine, and tries to find him a nicer coat. When he eventually tells her he's a police officer she presumes he means that he's undercover and that she won't tell anybody. (Either that, or she thinks he's delusional and only believes he's a cop.)
- In that same episode, Columbo pulls up to the scene of a crime, which happens to be a defunct auto shop. The officer on duty initially assumes that Columbo is there to get his car looked at and tells him the place is closed. Columbo identifies himself and the officer tells him where to find the man he's looking for. Columbo attempts to start the car to drive to the designated area, but it stalls out. He says, "I'll leave it here," and then leaves the car, unlocked and with the window rolled down, with the officer, who throws up his hands in exasperation.
- In the episode "Mind Over Mayhem," Columbo is introduced talking to a school official, who informs him that he will have to withdraw his student. It turns out it's an obedience school and they're talking about Dog. Then when Columbo gets called on the case:
Columbo: "Could I just leave him here for a couple hours while I go to work?"Official: "I'm afraid not. He demoralizes the other students."
- Columbo's entrance into the episode in "A Stitch in Crime", called into the scene exhausted and more bedraggled than usual due to how early it is. He keeps trying to crack an egg (his breakfast) on various things, including the victim's car. And then when they find the tire iron the woman was killed with...
Columbo: 'Scuse me, you wanna hold that over here for a minute? *Starts cracking his egg on the murder weapon.*
- In "Undercover," the fact that twice, while undercover as "Artie Stokes" and being sent to recover pieces of the puzzle mystery Irving Krutch has placed on him, Columbo approaches both Mo Weinberg and Geraldine Ferguson and both of them are fully convinced he's a cop, even when he says he isn't. The first scene with Geraldine is funnier because she's played by Shera Danese, Peter Falk's wife.
- This becomes even funnier when, after changing back into his usual clothes, he goes to visit the "D. McNally" on the list and is immediately mistaken for a hobo.
- At the end of the episode An Exercise in Fatality, Columbo is rummaging around in his bag for the evidence that will prove the murderer guilty (while the murderer waits, fuming) and pulls out a squashed package:
Columbo: "Oh, that's my lunch; that don't mean nothing..."
- A small bit in The Most Crucial Game: Paul Hanlon makes his trip to and from the murder scene disguised as an ice cream truck driver. On the way back, he helps himself to a popsicle.
- In The Bye, Bye Sky-High IQ Case, Columbo meets a witness in a restaurant, unconsciously bringing along a donut he picked up along the way. A surly waitress (played by a pre-Halloween Jamie Lee Curtis) tells him that he can only stay if he gets rid of the donut and orders something from the menu instead. Columbo takes the menu, studies it carefully, and orders...a donut.
- The series 5 episode Last Salute to the Commodore:
- The film opens with a group of people boating on a small motor ferry called "TITANIC" of all things. No, it doesn't sink, but it can be So Unfunny, It's Funny due to how random this is.
- It features not only a rare whodunit twist on the series instead of the usual howshegonnacatchim, but it also portrays Columbo at his snuggliest, constantly invading Charles' (Robert Vaughn) personal space to the point of repeatedly hugging him or sitting on him. Robert Vaughn can be seen barely keeping a straight face during these scenes.
- In "Now You See Him" Columbo's wife gets him a brand new coat. Being of course that's it new and stiff and not rumpled looking, he hates it and takes it off at every opportunity and conveniently "forgets" it everywhere. The grumpy way he takes the coat back when people remind him to take it with him is hilarious.
Columbo: I'll be a son of a gun. Where'd you find that? I've been looking all over for it.Wilson: In the lost and found. You left it at the cafeteria.Columbo: I thought someone stole it.Wilson: At police headquarters?
- Columbo's antics when goofing around with Ward Fowler in "Fade in to Murder", including pretending briefly to be a villain on Fowler's detective show (and unable to keep himself from laughing during it) and wearing his hat to pose like Fowler's publicity poster.
- An example of Columbo's Deadpan Snarker tendencies in Murder Under Glass when he arrives at the killer's house and is greeted by his secretary:
Columbo: "Good evening, ma'am. My name is Lieutenant Columbo, homicide. I'd like to speak to Paul Gerard; is he home?"Eve Plumber: "I...I'm not sure."Columbo: "Is it a big place, or is he just out to the police?"
- The entirety of the Alias crossover short.
- In "Caution: Murder Can Be Hazardous to Your Health" when Columbo is on his way to question the owner of an adult shop, two prostitutes try to flirt with him. Upon reaching the shop, he meets a customer that's wearing the exact same clothes he is, and is mistaken for a fellow pervert.