The Karlsruher Fußball-Verein e. V. is a German association football club that plays in Karlsruhe, Baden-Württemberg. Established on 17 November 1891, KFV was a founding member of the German Football Association in 1900 and is the oldest still existing football club in Southern Germany. The club was one of the leading German football clubs before the First World War. The team went on to capture the national championship in 1910 with a 1–0 victory over Holstein Kiel, but lost the final in 1905 and 1912. The KFV claimed the Southern German football championship from 1901 to 1905 and from 1910 to 1912. After a financial collapse and a resulting disqualification from league operations in 2004, the club continued its activities in 2007.

Kieler Sportvereinigung Holstein von 1900 e.V., simply as KSV Holstein or Kieler SV Holstein, commonly known as Holstein Kiel, is a German association football and sports club based in the city of Kiel, Schleswig-Holstein. From the 1900s through the 1960s, the club was one of the most dominant sides in northern Germany. Some notable honors from that period include the German football championship in 1912, and being vice-champions 1910 and 1930. Holstein also won six regional titles and finished as runners-up another nine times. They remained a first-division side until the formation of the Bundesliga in 1963. They will make their debut in the Bundesliga in the 2024-25 season after gaining promotion from the 2. Bundesliga in 2024.