Original Sondico football shirt Carlisle United F.C. 2014/15

Carlisle United Football Club is a professional association football club based in Carlisle, Cumbria, England. The team compete in EFL League Two, the fourth tier of the English football league system. They have played their home games at Brunton Park since 1909. The club's traditional kit is blue with white and red detail, whilst the badge takes elements from the city's coat of arms by including two wyverns. They are nicknamed the "Blues", due to their kit, as well as the "Cumbrians". The club is the closest English professional football club to the Anglo-Scottish border.

Formed in 1904, the club entered the Lancashire Combination the following year and were crowned Division Two champions in 1906–07. They entered the North Eastern League in 1910 and went on to win the league title in 1921–22, before being elected into the Football League in 1928. They spent the next 30 years in the Third Division North, at which point they were assigned a place in the newly formed Fourth Division, from where they won promotion in 1961–62. Relegated the following season, they then won two consecutive promotions, finishing the 1964–65 season as champions of the Third Division under the stewardship of Alan Ashman. They secured promotion out of the Second Division in 1973–74, but stayed only one season in the First Division and were relegated back to the Third Division at the end of the 1976–77 campaign. Promoted again under Bob Stokoe in 1981–82, they suffered successive relegations to return to the fourth tier by 1987.

Carlisle won promotion as champions of the fourth tier in 1994–95, but were relegated the next season, before winning promotion again in 1996–97, only to be relegated again the following year. Their 76-year stay in the Football League came to an end with relegation in 2003–04, though player-manager Paul Simpson secured an immediate return after leading United to victory in the 2005 Conference National play-off Final. They then won the League Two title in 2005–06, and remained in League One until their relegation at the end of the 2013–14 season. The club has reached the final of the Football League Trophy six times, more than any other team, winning it in 1997 and 2011, and finishing as runners-up in 1995, 2003, 2006 and 2010.