During the first season of the series, Joe Mannix works for a large Los Angeles detective agency called Intertect, which was the planned original title of the show. His superior is Lew Wickersham, played by Joseph Campanella, with the agency featuring the use of computers to help solve crimes. As opposed to the other employees who must wear dark suits and sit in rows of desks with only one piece of paper allowed to be on their desks at one time, Mannix belongs to the classic American detective archetype, thus he usually ignores the computers' solutions, disobeys his boss's orders, and sets out to do things his own way. He wears plaid sport coats and has his own office that he keeps sloppy between his assignments. Lew has cameras in all the rooms of Intertect monitoring the performance of his employees and providing instant feedback through intercoms in the room. Unlike the other Intertect operatives, Mannix attempts to block the camera with a coat rack and insults Lew, comparing him to Big Brother.
To improve the ratings of the show, Desilu head Lucille Ball and producer Bruce Geller made some changes, making the show similar to other private-eye shows. Ball thought the computers were too high-tech and beyond the comprehension of the average viewer of the time and had them removed.
From the second season on, Mannix works on his own with the assistance of his loyal secretary Peggy Fair, a police officer's widow played by Gail Fisher – one of the first African American actresses to have a regular series role. He also receives help from the Los Angeles police department, the two most prominent officers being Lieutenant Art Malcolm (portrayed by Ward Wood) and Lieutenant Adam Tobias (portrayed by Robert Reed). Other police contacts are Lieutenant George Kramer (Larry Linville), who had been the partner of Peggy's late husband, and Lieutenant Dan Ives (Jack Ging).
In the 1969 season, he also employs the services of a competitive private investigator, Albie Loos (performed by Joe Mantell), as a sort of investigative gofer. In the 1972 season, Albie returns, played by a different actor (Milton Selzer).
While Mannix was not generally known as a show that explored socially relevant topics, several episodes had topical themes. Season two had episodes featuring compulsive gambling, deaf and blind characters who were instrumental in solving cases in spite of their physical limitations, and episodes that focused on racism against Blacks and Hispanics. Season six had an episode focusing on the effects the Vietnam War had on returning veterans, including the effects of PTSD.
Joseph R. "Joe" Mannix is a regular guy, without pretense, who has a store of proverbs on which to rely in conversation. What demons he has mostly come from having fought in the U.S. Army during the Korean War, where he was initially listed as MIA while he was a prisoner of war in a brutal POW camp until he escaped. Over the length of the series, a sizable percentage of his old Army comrades turn out to have homicidal impulses against him, as does his fellow running back from his college football days. During the series, Mannix is also revealed to have worked as a mercenary in Latin America. Like the actor who plays him, Mannix is of Armenian descent. He speaks fluent Armenian from time to time during the series, as well as conversational Spanish.
Mannix is notable for the high level of physical punishment he withstands. During the course of the series, he is shot and wounded over a dozen separate times, and knocked unconscious around 55 times. He frequently takes brutal beatings to the abdomen; some of these went on quite a long time, particularly by the television standards of the era. Whenever he gets into one of his convertibles, he can expect to be shot at or run off the road by another car or find his vehicle sabotaged. Nevertheless, he keeps his cool and perseveres until his antagonists are brought down. While making the television pilot "The Name is Mannix", Connors dislocated his shoulder running away from a From Russia with Love-type pursuit from a helicopter, and broke his left wrist punching a stuntman who happened to be wearing a steel plate on his back. This character aspect was lampooned multiple times by radio comedians Bob and Ray, as "Blimmix", portrayed as dim-witted, and ending with Blimmix being soundly beaten by his adversary. These parodies retained the Lalo Schifrin composed theme song at the beginning and conclusion.
Connors later expressed his concerns over what he saw as the show's dismissive attitude toward violence and its consequences, citing the example of Mannix being thrown down a flight of stairs and appearing without a scratch almost immediately after.
Starting in season two, Mannix lives at 17 Paseo Verde, West Los Angeles. Mannix grew up in a town called Summer Grove, where he was a star football and basketball player. Summer Grove had a thriving Armenian immigrant community. As of 1969, Mannix's mother had died 10 years earlier, and Mannix had not been back to the town since the funeral. Mannix's estranged father, Stefan, was still living in Summer Grove, and Mannix and his father would start a reconciliation. When Mannix returns to Summer Grove for a case three years later, his father and he are on good terms. Following military service in the Korean War, Mannix attended Western Pacific University on the GI Bill, graduated in 1955, and obtained his private investigator's license in 1956. He is a black belt in karate. Throughout the series, he appears proficient in a variety of athletic pursuits, including sailing, horseback riding, and skiing. He is an accomplished pool player, golfs regularly, and is also a skilled airplane pilot. In the first season, he carries a Walther PP semiautomatic pistol. From the second season on, Mannix carries a Colt Detective Special snubnosed revolver in .38 Special caliber.
In 1971, Connors guest-starred on an episode of Here's Lucy entitled "Lucy and Mannix are Held Hostage".
In 1997, Connors reprised the role of Mannix on an episode of Diagnosis: Murder entitled "Hard-Boiled Murder", which serves as a sequel to the Mannix episode "Little Girl Lost".
"Mannix" was used as a reference several times by Mystery Science Theater 3000 whenever there was a foot chase or a fight.
Gary Morton, the husband of Lucille Ball and head of Desilu Studios, noticed a 1937 Bentley convertible being driven by Mike Connors. A car enthusiast, Morton began talking about cars to Connors when he remembered a Desilu detective show coming up in which he thought Connors would do well.
Mannix was initially a production of Desilu Productions, which had been purchased by Gulf + Western earlier in 1967. During the first season, Gulf + Western integrated Desilu's operations into its Paramount Pictures subsidiary and the company became Paramount Television.
Mannix featured a dynamic split-screen opening credits sequence set to theme music from noted composer Lalo Schifrin. Unusual for a private detective series, the Mannix theme is in triple time, the same signature used for waltzes.
The show's title card, opening credits, and closing credits roll are set in variations of the City typeface, a squared-off, split-serif face that was long used by IBM Corporation as part of their corporate design and still appears in their logo. This refers to the computers used by Intertect in the first season. The dot over the "i" in Mannix had the appearance of a computer tape reel. This was removed after the first season.
Over the life of the series, several famous entertainers were featured in one-time roles, including Neil Diamond and Buffalo Springfield as themselves and Lou Rawls as a club singer, Rich Little as an impressionist, and Milton Berle as a stand-up comedian. Essay humorist Art Buchwald also had a cameo role unrelated to journalism, and in another episode, Rona Barrett played herself.
The automobile was a focus of Mannix's professional life, and he had several of them as his personal vehicle in the eight-year run of the series. Those were:Season 1 – 1966 Mercury Comet Caliente convertible (pilot episode: "The Name Is Mannix"), 1967 Mercury Comet Cyclone convertible (one episode only: "Skid Marks on a Dry Run"), 1967 Ford Galaxie 500 four-door hardtop then a 1967 Ford Fairlane 500 four-door sedan after the Galaxie got shot up – both were Intertect company cars (one episode only: "The Cost of a Vacation"). In all other season-one episodes, Mannix drove a 1967 Oldsmobile Toronado roadster customized by George Barris, builder of TV's Batmobile from the 1960s Batman ABC series, since the producers wanted a convertible and Oldsmobile never produced an open-topped Toronado. Because of a change in episode run order ("The Cost of a Vacation" was the second episode of Mannix shot after the pilot, although it was the sixth episode CBS broadcast), the one-shot appearances of the Galaxie and Fairlane were after the Toronado had been established as Mannix's car.
Season 2 – 1968 Dodge Dart GTS 340 convertible "kustomized" by George Barris with functional hood scoops, Lucas Flamethrower driving lights, blacked-out grille, racing-style gas filler cap, molded-in rear spoiler, blacked out tail light panel, and custom tail light lenses. The car was originally red, but Executive Producer Bruce Geller wanted it changed to a British Racing Green, which Barris did. (This car still retains its original red paint under the carpet.) A Motorola car-phone (a remarkably expensive and rare item in 1968) was installed. Rader mag wheels like those on the Batmobile were originally installed by Barris, but changed later in the '68 season to Cragar S/S chrome wheels. George Barris also installed his own "Barris Kustoms" emblem on the lower part of each front fender. No duplicate 1968 Mannix Darts were built; it is a "1 of 1" car. This car was used in both the 1968 and '69 seasons of Mannix.
Though a ’69 Dart was built by Barris to replicate this car in the show's 1969 season, the ’68 Dart was regularly seen during the ’69 season. (In the 1969 episode "A Penny for the Peep Show", both the ’68 and ’69 Darts are used in the same shot, to elude a police tail on Mannix, but no explanation in the episode was given forwhy or how two identically customized green Dart convertibles show up together.) In further tracing the car's history, the '68 Dart was reportedly sold to a secretary at Paramount Studios and then was lost for decades until being discovered near a ranger station in the California mountains. It has since been restored to its original Mannix/Barris condition and was featured in Hemmings Muscle Machines, December 2009 issue.
The '68 Mannix Dart and its intriguing history was also featured on the TV show Drive on Discovery HD Theater in 2010. The TV show reunited the car with Mike Connors for the first time in over 40 years. The car is currently owned by C. Van Tune, former editor-in-chief of Motor Trend magazine, who conducted the TV interview with Mike Connors and who also wrote an article on the Mannix Dart for the summer 2011 issue of Motor Trend Classic magazine. In that article, the Dart is reunited with Mike Connors, George Barris, and Mannix stuntman Dick Ziker.
Another article on the famous Dart was published in the October 2011 issue of Mopar Action magazine. An article in the New York Times (July 22, 2012) included information on the 1968 Mannix Dart and a recent photo of Mike Connors with the car. The Mannix Dart was also mentioned on Sirius/XM Radio's "60s on 6" channel by disc jockey Mike Kelly.Season 3 – 1969 Dodge Dart GTS 340 convertible "kustomized" by George Barris to replicate the '68 Dart: This car was totalled in a wreck soon after being sold, following its use on the series.
Season 4 – 1970 Plymouth Cuda 340 dark green convertible
Season 5 – 1971 Plymouth Cuda convertible, actually, three 1971s (all dark green with green interiors and black soft tops), were supplied by Chrysler Corporation, and all had differently sized (318, 340, 383) engines. One was wrecked, but later repaired. One episode the hood is raised, dynamite discovered, and the air cleaner reads 383.
Season 6 – 1973 Plymouth Cuda convertible (actually two of the 1971 cars updated with 1973 grilles, headlamps, front fenders, front/rear bumpers, and tail lights)
Season 7 – 1974 Dodge Challenger 360 Coupe: Two were built especially for the show, and had every available option installed, including the rare factory sunroof. Mild Barris customizing included Cragar S/S 15-inch chrome wheels, G60x15 Goodyear radial tires, and an upper body pinstripe.
Season 8 – Chevrolet Camaro LT
Peggy Fair's cars were less prominent, but in seasons two through eight, they included a Simca 1000, Simca 1204 hatchback, Dodge Colt hardtop, and finally a Chevrolet Vega hatchback.
For his work on Mannix, Mike Connors was nominated for four Golden Globe Awards, winning once, and for four Emmy Awards. Gail Fisher was nominated for four Emmy Awards, winning once, and for three Golden Globe Awards, winning twice.
The series was twice nominated for the Emmy Award for Best Dramatic Series, and four times for the Golden Globe Award, winning once. In 1972, writer Mann Rubin won an Edgar Award from the Mystery Writers of America for the episode "A Step in Time".
In May 2011, Connors filed suit in Los Angeles Superior Court against Paramount and CBS Television Studios, claiming that he was never paid royalties from the Mannix series.
Mannix has been the subject of a recent book-length study by JoAnn Paul, entitled “and now, back to mannix”. Paul’s study could be described as having two distinct purposes.
First, Paul attempts to highlight the value of Mannix purely as a television show, underlining distinctive characteristics of the show in contrast to similar shows, various ways in which Mannix was pioneering for its time, and especially the way the show is primarily character driven rather than plot driven. Paul claims that it is especially the fact that Mannix explored the character of Joe Mannix, rather than being solely about an interesting plot, that makes the show both unique and attractive to viewers.
Second, Paul also sees in Mannix—both the show in general and the character in particular—the telling of a "myth" in the sense that mythologist Joseph Campbell and psychologist Carl Jung speak of “myth”. For Paul, Mannix represents the archetypal “hero’s myth” and Joe Mannix the figure of the hero. Paul sees Joe Mannix as a man driven by certain significant and, in essence, ethical ideals, who tries to live by those ideals in the face of often extraordinary adversity. In this respect, Paul claims, Joe Mannix plays the role of the hero in myth, something which especially draws viewers and fans to the show.
CBS Home Entertainment (distributed by Paramount) has released all eight seasons of Mannix on DVD in Region 1.
On May 9, 2017 CBS DVD will release Mannix- The Complete series on DVD in Region 1.
In Region 4, Shock has released the first three seasons on DVD in Australia.