Derby County Football Club is a professional association football club in Derby, England. The club compete in the Championship, the second tier of English football. Notable for being one of the twelve founder members of the Football League in 1888, it is one of only ten clubs to have competed in every season of the English football league system and, in 2009, was ranked 137th in the top 200 European football teams of the 20th century by International Federation of Football History and Statistics. Derby County F.C. was founded in 1884, by William Morley, as an offshoot of Derbyshire County Cricket Club; it has spent all but four seasons in the top two divisions of English football. The club's competitive peak came in the 1970s when they were twice English League Champions and competed in major European competitions on four separate occasions, reaching the European Cup semi-finals, as well as winning several minor trophies. Additionally, the club was a strong force in the interwar years and won the 1945–46 FA Cup. The club adopted its now traditional black and white club colours in the 1890s and appropriated its club nickname The Rams, a tribute to its links with the First Regiment of Derby Militia, which took a ram as its mascot and the song "The Derby Ram" as its regimental song, at the same time. Home games are played at the iPro Stadium, located in Pride Park, Derby, where the club moved in 1997.

Pride Park Stadium is an all-seater football stadium in Derby, England, which is the home ground of English Football League club Derby County. With a capacity of 33,597, it is the 16th-largest football ground in England. Pride Park is a business park on the outskirts of Derby city centre, and the stadium was built as part of the commercial redevelopment of the area in the 1990s. Derby County have played at the ground since it opened in 1997 as a replacement for the Baseball Ground. Pride Park has hosted two full international matches, England v. Mexico in 2001 and Brazil v. Ukraine in 2010, several England under-21 matches, and the 2009 FA Women's Cup final. It also hosted the 2025 Women's League Cup Final.