The car driven by Columbo is a 1959 Peugeot 403 convertible. Only five hundred four two-door convertibles were made in 1959. The original was sold when NBC dropped the series, and a replacement had to be located when ABC resumed production. During the NBC years, the license plate was 044-APD. For the show's ABC run, the plate was 448-DBZ.

Columbo's first name is never uttered throughout the series. In one episode, however, his badge was briefly shown, listing his full name as Frank Columbo. A Canadian trivia game once claimed his first name was "Phillip". Series co-Creator William Link has said that as far as he is concerned, neither one is correct, and Columbo has NO first name besides "Lieutenant".

Season one, episode one, "Murder by the Book", was directed by Steven Spielberg and written by Steven Bochco. Spielberg was never again involved with the series, though still honored its career influence when he attended a support event for "The Rose Theatre", attended by Peter Falk and many other cast. Bochco wrote several other episodes.

Peter Falk's real-life wife Shera Danese appeared in six episodes, each time as a completely unique character.

The character and show, created by Richard Levinson and William Link, popularised the inverted detective story format, which begins by showing the commission of the crime and its perpetrator; the plot therefore usually has no "whodunit" element, and instead revolves around how a perpetrator known to the audience will finally be caught and exposed (sometimes referred to as a "howcatchem").

Columbo's wardrobe was personally provided by Peter Falk; they were his own clothes, including the high-topped shoes and the shabby suit, Falk had bought the famous raincoat (which made its first appearance in Prescription: Murder (1968). ) when caught in a rainstorm in New York in 1967. It cost him $15. He also added the cigar as a personal touch; Falk was a lifelong cigarette smoker.

Peter Falk frequently added in unscripted moments and ad-libs such as asking for a pencil, searching for something in his pockets, asking a character to repeat something, mumbling about irrelevant trivialities, or adding in a line about Mrs. Columbo. He did this to elicit a natural and surprised reaction from his fellow actor, usually the suspect.

Originally, Bing Crosby was offered the role of Columbo. However, citing the fact that he didn't want to commit to a series, he refused the role. He also said, jokingly, that doing the series would interfere with his golf game.

The original character concept for Columbo was as a smooth talking, polished, suave personality. Peter Falk brought an entirely different and humorous dimension to the role with his aimless chattering, scattered mannerisms and disheveled appearance. Although the producers were uncertain if audiences would accept a police detective looking like a bum, the show's premier was an instant hit.

Columbo often refers to his wife Mrs Columbo, although she has never been seen on screen. However, Columbo is sometimes seen talking on the telephone with her and other characters describe meeting her. Interestingly, her first name is never revealed, either.

Columbo's Pugeot convertible can be seen on the Universal Studios tour.

Peter Falk himself directed the last episode of the first season, "Columbo: Blueprint for Murder (1972)".

A few years prior to his death, Peter Falk had expressed interest in returning to the role. In 2007, he claimed he had chosen a script for one last Columbo episode, "Columbo: Hear No Evil". The script was renamed "Columbo's Last Case". ABC declined the project. In response, producers for the series announced that they were attempting to shop the project to foreign production companies. However, Falk was diagnosed with dementia in late 2007.

Peter Falk appeared in character as Columbo at The Dean Martin Celebrity Roast of Frank Sinatra in 1978. He asked for an autograph to be dedicated to Rose, his wife.

The original plan was that a new Columbo episode would air every week, but as a motion picture star, Peter Falk refused to commit to such an arduous schedule, which would have meant shooting an episode every five days. The network arranged for the Columbo segments to air once a month on Wednesday nights.

When Columbo was renewed for a second season, NBC brass had a request: They wanted the lieutenant to have a sidekick. Perhaps a young rookie detective just learning the ropes. Link and Levinson were resistant to the idea, but the network was pressuring them. They conferred with Steven Bochco, who was writing the script for the season opener, "Etude in Black," and together they hatched the idea of giving Lt. Columbo a dog as a "partner." Falk was against the idea at first; he felt that between the raincoat, cigar, and Peugeot his character had enough gimmicks. But when he met the lethargic, drooling Basset Hound that had been plucked from a pound, Falk knew it was perfect for Columbo's dog.

Although Columbo talks about his wife in many episodes, he mentions having a sister once in the 1968 pilot, Prescription: Murder.

In 1997, "Columbo: Murder by the Book (1971)", directed by Steven Spielberg, was ranked No. 16 on TV Guide's 100 Greatest Episodes of All Time.

Columbo received numerous awards and nominations from 1971 to 2005, including 13 Emmys, two Golden Globe Awards, two Edgar Awards and a TV Land Award nomination in 2005 for Peter Falk.

Peter Falk wasn't too far removed from the character he played. In real life he tended to be rumpled and disheveled and was forever misplacing things (he was famous for losing his car keys and having to be driven home from the studio by someone else). He was also intelligent, having earned a master's degree in Public Administration from Syracuse University, which led to him working for the State of Connecticut's Budget Bureau as an efficiency expert until the acting bug bit him. He was also used to being underestimated due to his appearance; he'd lost his right eye to cancer at age three, and many of his drama teachers in college warned him of his limited chances in film due to his cockeyed stare. Indeed, after a screen test at Columbia Pictures Harry Cohn dismissed him by saying, "For the same price I can get an actor with two eyes."

Patrick McGoohan appeared four times. Interestingly enough, each appearance was in the third episode of the particular season.

The theme song for the series is "This Old Man".

During a 2009 court trial over Peter Falk's care, Dr Stephen Read stated that the actor's condition had deteriorated so badly that Falk could no longer remember playing a character named Columbo, nor could he identify who Columbo was. Falk died on June 23, 2011, aged 83.

Peter Falk would often ad lib his character's idiosyncrasies (fumbling through his pockets for a piece of evidence and discovering a grocery list, asking to borrow a pencil, becoming distracted by something irrelevant in the room at a dramatic point in a conversation with a suspect, etc.), inserting these into his performance as a way to keep his fellow actors off-balance. He felt it helped to make their confused and impatient reactions to Columbo's antics more genuine.

Some of the episodes established that Columbo carried a Colt snub-nosed revolver in his raincoat, which he pulled in rare episodes, and would occasionally remark that his wife, 'the Mrs.', would not allow him to buy a new car because it 'wasn't necessary', portraying the detective throughout the series as permanently driving an aged and battered 1959 Peugeot 403 Cabriolet.

Columbo was an immediate hit in the Nielsen ratings and Peter Falk won an Emmy Award for his role in the show's first season.

Peter Falk, as Lieutenant Columbo, played essentially the same part, in the same way, that he played Police Lieutenant Bixbee in Penelope (1966).

Despite "Columbo" being an actual Italian last name, in Italy, the character and series name was changed to "Colombo".

Eight years before Peter Falk played Columbo, Bert Freed played the role for an episode of The Chevy Mystery Show (1960).

Unlike his cigar-smoking character, Peter Falk was a lifelong cigarette smoker.

Two episodes, "Columbo: No Time to Die (1992)" and "Columbo: Undercover (1994)", were based on the 87th Precinct novels by Ed McBain (AKA Evan Hunter), and therefore do not strictly follow the standard Columbo/inverted detective story format.

Episodes of Columbo are between 73 and 98 minutes long, and have been broadcast in 44 countries.

Even though Peter Falk immediately made the Columbo character his own, he was actually the third actor to play the role. Previous attempts had been performed in the theatre and on live television.

The 1979 TV series entitled Mrs. Columbo was not technically related to the original Peter Falk series. In fact, Levinson and Link opposed the entire concept of the series; it was NBC honcho Fred Silverman who gave the OK to use the Columbo name and imply that Kate Mulgrew was the widowed/divorced wife (the series changed names and backstories several times during its short run) of the famed homicide detective. The "real" Mrs. Columbo was never mentioned by her first name during the original series, but actor Peter Falk possibly slipped and revealed that her name was "Rose" when he appeared at this Dean Martin Roast saluting Frank Sinatra and asked for an autograph.

Richard Levinson and William Link met in junior high, kicking off a writing partnership that lasted until Levinson's death in 1987. The two put their stamp on a variety of '70s detective programs (Mannix, Ellery Queen), continuing on into the '80s (Murder, She Wrote).

The character of Columbo was created by the writing team of Richard Levinson and William Link, who said that Columbo was partially inspired by Fyodor Dostoevsky's Crime and Punishment character Porfiry Petrovich as well as G.K. Chesterton's humble cleric-detective Father Brown. Other sources claim Columbo's character is also influenced by Inspector Fichet from the French suspense-thriller film Diabolique (1955).

As Mrs Columbo was never seen there was speculation that Columbo was not actually married.

There are theories that Mrs Columbo was not real but a technique used by Columbo to confuse the murderers or direct the conversation in a particular way. However, these are in fact invalid as there are numerous episodes wherein other characters have seen and/or spoken with Mrs Columbo. An example of this the scene in Troubled Waters (1975) in which Columbo is on the ship looking for his wife and Captain Gibbon (the captain of the ship) states that he has spoken with Mr Columbo, as "Columbo" is a name he could not forget. However, this does not mean that the anecdotes his uses about his wife are true, but could be used to steer conversations towards his questions.

Columbo's catchphrase is often misquoted as being "just one more question" when in fact Columbo more often says "just one more thing".