Cagney & Lacey is an American police procedural drama television series that aired on the CBS television network for seven seasons from March 25, 1982, to May 16, 1988. The show is about two New York City police detectives who lead very different lives: Christine Cagney (Sharon Gless) is a career-minded single woman, while Mary Beth Lacey (Tyne Daly) is a married working mother. The series is set in a fictionalized version of Manhattan's 14th Precinct (known as "Midtown South"). The pilot movie had Loretta Swit in the role of Cagney, while the first six episodes had Meg Foster in the role. When the show was revived for a full-season run, Gless took over the role and remained in the part for the rest of the show's run and later television movies. Each year during that time, one of the two lead actresses won the Emmy for Best Lead Actress in a Drama (four wins for Daly in 1983, 1984, 1985 and 1988; and two wins for Gless in 1986 and 1987), a winning streak matched only once since in any major category by a show. John Karlen also won the Emmy for Best Supporting Actor in a Drama in 1986 for his role as Harvey Lacey Sr., and the Cagney & Lacey series itself won the Emmy for Outstanding Drama in 1985 and 1986.

Producer Barney Rosenzweig was influenced by the feminist movement through his then-girlfriend Barbara Corday, who recommended to him Molly Haskell's book From Reverence to Rape which analyses depictions of women in film. Haskell's book claimed there had never been a female buddy film, and Rosenzweig sought to make one, a comedy initially titled Newman & Redford (before changing the title for legal reasons). Corday and Barbara Avedon wrote the script. No studio wanted to make the film, so Corday considered taking it to television. Rosenzweig took the script, removed the main plot (leaving only the character development), and took it to all networks, but only CBS was interested.

Actress Loretta Swit played the role of Christine Cagney in the original television movie (October 1981), but was forced to decline the role in the series when the producers of M*A*S*H refused to let her out of her contract. When the movie was picked up as a series, first airing with six episodes as a midseason replacement in the spring of 1982, Meg Foster portrayed the character. When the show was picked up for a regular season in 1982, Foster was replaced with Sharon Gless because CBS deemed Foster too aggressive and too likely to be perceived as a lesbian by the viewers.

CBS executives hoped Gless would portray Cagney as more feminine and attempted to pressure the producers to remake Christine into a more "high-class", snobbish woman from wealthy parents. The pilot had portrayed Cagney as an ex-glamour model. Barney Rosenzweig and Barbara Corday initially refused to change Cagney from a tough, witty, working-class woman. Shortly into Gless's tenure on the program, Rosenzweig and Corday compromised with the network brass. They further developed Cagney's background, explaining gradually in a loose storyline that she may have been born to a somewhat well-to-do professional mother, Maureen, who had a relationship with police officer Charles Cagney (Dick O'Neill), who came from working-class roots. They separated soon after Christine and her brother Brian (David Ackroyd) were born. She was partially raised in an uptown Westchester world, which she appreciated; however, the trappings of the upper-middle social strata sometimes drove her to miss her father's lifestyle, and she and her father therefore established a special bond.

Cagney was a bit quieter and more reserved than her vivacious, talkative, loud partner Mary Beth Lacey, but could still relate to the world with attitudes that could be shared by people across the social spectrum.

Al Waxman co-starred as Cagney and Lacey's good-natured and sometimes blustery supervisor, Lt. Bert Samuels. Carl Lumbly and Martin Kove played fellow detectives Marcus Petrie and Victor Isbecki. Sidney Clute played veteran detective Paul LaGuardia. John Karlen co-starred as Mary Beth's husband, Harvey Lacey, and Tony La Torre and Troy Slaten played their sons Harvey Lacey Jr. and Michael Lacey. Harvey Atkin played desk sergeant Ronald Coleman. Jason Bernard had the recurring role of Deputy Inspector Marquette during the first two seasons. When the show was brought back in March 1984, Marquette had been replaced by Dep. Inspector Knelman (Michael Fairman), who lasted the rest of the series. In the fourth season, Christine entered a relationship with Sgt. Dory McKenna (Barry Primus), who battled drug addiction. After a tumultuous courtship, Christine left him and soon after took up with a more stable suitor, attorney David Keeler (Stephen Macht).

On October 2, 1985, Clute died of cancer at age 69. He had completed filming a few episodes of the 1985–86 season. Det. LaGuardia's disappearance from the show was explained by saying he had retired from the 14th Precinct and moved to New Jersey with a new female companion less than half his age. To honor Clute, the producers kept his name in the opening credits for the rest of the series.

LaGuardia was replaced in the fifth season with Det. Jonah Newman (Dan Shor), a boyish ingenu with an elevated sense of himself. Newman, while popular with the guys, was not above stepping on anyone in order to get the coveted promotion of Detective Second Grade. As a result, Chris and Mary Beth had a strained relationship with him. Newman developed a crush on Chris but she never knew. Eventually, Newman was partnered with veteran Al Corassa (Paul Mantee), who became a regular midway through season five (Mantee had made three guest appearances in late 1985, in which his character's name was Det. Thomas in the first two episodes, and Corassa in the third) and took up the role of experienced cop that LaGuardia had vacated. Their partnership met a sad end in May 1986, when Newman was killed by a random gunshot outside of the local district court, just after receiving his promotion to Second Grade.