Taggart is a Scottish detective fiction television programme created by Glenn Chandler, who wrote many of the episodes, and made by STV Studios for the ITV network. It originally ran as the miniseries Killer from 6 until 20 September 1983, before a full series was commissioned that ran from 2 July 1985 until 7 November 2010. The series revolved around a group of detectives initially in the Maryhill CID of Strathclyde Police, though various storylines were set in other parts of Greater Glasgow and in other areas of Scotland. The team operated out of the fictional John Street police station. Mark McManus, who played the title character Jim Taggart, died in 1994. However, the series continued under the same name. Taggart is one of the UK's longest-running television dramas.

The Scottish BAFTA-winning pilot episode "Killer", directed by Laurence Moody and broadcast in 1983, introduced the character Detective Chief Inspector Jim Taggart (played by Mark McManus until his death in 1994), a tough and experienced detective who had worked his way up through the ranks. His original sidekick was Detective Sergeant Peter Livingstone (Neil Duncan). Livingstone represented the new breed of young graduates entering the police force and frequently had a difficult relationship with Taggart as a result. Taggart's boss in the pilot was Superintendent Robert Murray (Tom Watson), and his boss after the second episode, "Dead Ringer", was Superintendent Jack McVitie (Iain Anders). Another important character was Taggart's wife Jean (Harriet Buchan), whose physical disability did not prevent her from pursuing a number of interests in life, while her cynical husband stuck mainly to his job. Throughout the McManus era, there was nearly always a sub-plot in every episode which involved the domestic life of the Taggarts, which on occasion became intertwined with the case being investigated. The most memorable of these was the Taggarts' ongoing care of Jean's senile Aunt Hettie (Sheila Donald), whom Jim despises and begrudges staying in his house. This sub-plot ran through 1990–91 until the Hettie character was killed off in the 1991 season finale, "Violent Delights", in which her funeral is carried out by a firm of undertakers who are also the subject of Taggart's investigation.

In 1987 the character of Michael Jardine (James MacPherson) was introduced. Neil Duncan left the series in 1987 and in 1990 a new female sidekick Jackie Reid (Blythe Duff) was introduced.

McManus died in 1994 during the filming of an episode. Taggart's absence in the broadcast story was explained by his being in meetings with the Chief Constable throughout. In 1995 the episode "Black Orchid" opened with Taggart's funeral. Despite the death of the title character the series continued. Jardine was promoted to Detective Inspector and DC Stuart Fraser (Colin McCredie) was introduced, becoming the long-suffering sidekick to Jardine, former long-suffering sidekick to Taggart. Fraser was later revealed to be gay. McCredie had made an early appearance in Taggart when he played a suspect part of a youth gang. DI Robbie Ross (John Michie) joined the team in 1998. Michie had made an early appearance in Taggart in 1990 when he played a suspect called Robby Meiklejohn in an episode called "Love Knot".

When MacPherson left the series in 2002 his character was killed off and replaced with DCI Matt Burke, formerly of Special Branch, played by Alex Norton, who had previously appeared in the series playing murder suspect George Bryce in 1986 in the episode "Knife-Edge". The personal relationships of the police officers in this series were shown as nothing to be envious of: Reid described herself, Burke, Ross and Fraser as "three divorcees and a celibate homosexual" in the episode "Penthouse and Pavement". After filming was completed on series 26 in December 2009, Colin McCredie was informed that he and his character would not be returning for filming of the next series.

ITV plc, the company that operates the ITV network franchises in England, Wales and southern Scotland, failed to announce whether it planned to show any new episodes of Taggart, prompting STV to suspend production of the programme in September 2009. STV announced in November 2009 that it would produce new episodes of Taggart for broadcast in 2010 regardless of whether ITV plc decided to screen it.

In February 2010 it was announced that ITV and STV had put their wider commercial differences to one side to make a new series, which Scottish viewers got to see first. The two broadcasters co-commissioned a six-part series of the show; UKTV also invested in return for repeat rights. New episodes of Taggart debuted on STV in autumn 2010 before being broadcast on ITV across the rest of the UK in 2011. The UKTV Channel Alibi showed the episodes in 2013. Online catch-up of the new series was not available to users of STV Player until the show had been broadcast on ITV and UTV.

The format of the show changed over the years. Originally the show ran with three one-hour episodes to each story. This was later changed starting with the last transmitted story in 1998 to a regular pattern of two-hour stand-alone stories and beginning in July 2002 these were shortened to 60 minutes. After a two-hour special episode in January 2003 episodes were again lengthened starting in October, this time to 90 minutes continuing through the 2008 New Year special "Genesis". After this the show became a series of one-hour stand-alone stories for the first time since 2003.