FC St. Gallen 1879 was founded on 19 April 1879, with its inaugural meeting held at the Restaurant Hörnli on Neugasse. It was founded by young businessmen who had been introduced to football while studying with English students. It is the oldest football club in Switzerland and is regarded as one of the oldest in continental Europe. The club adopted the name FC St. Gallen officially on 22 June 1903. Its first head coach, in 1912, was the Englishman Jack Reynolds, later a manager of Ajax. The club's colours are green and white, and its nickname, Espen (aspens), comes from its former ground, Espenmoos.
The club won its first Swiss championship in 1903–04 and its next only in 1999–2000, after 96 years. The 2000 title was won by the team of coach Marcel Koller, who was voted Swiss manager of the year and later coached the national teams of Switzerland and Austria. A year after the title St. Gallen came close to another: on the final day of 2000–01 it lost 4–0 at home to Grasshoppers and missed out on the championship.
The club won its first Swiss Cup in 1969, beating Bellinzona 2–0 in the final. In later decades it reached several more finals, including in 1977 and 1998, and in 2021 and 2022, under coach Peter Zeidler, it lost two in a row. Only on 24 May 2026 at the Wankdorf in Bern, 26 years after the league title, did it win a second Swiss Cup, beating second-tier Stade Lausanne-Ouchy 3–0 despite a red card for goalkeeper Lukas Watkowiak just before half-time. The goals were scored by Tom Gaal, Lukas Görtler and Christian Witzig, and the team was coached by Enrico Maaßen. Earlier in 2025–26 St. Gallen finished second in the league.
The club's most famous European result came in 2000–01. As Swiss champions, St. Gallen played Galatasaray in the third qualifying round of the Champions League and went out 4–3 on aggregate, then eliminated Chelsea in the first round of the UEFA Cup. It won 2–0 at home, lost 1–0 in London and went through 2–1 on aggregate. In the second round it was stopped by Club Brugge (1–1 and 1–2). A year later, in the UEFA Cup, St. Gallen eliminated Steaua Bucharest (3–2 on aggregate) and went out against Freiburg. Earlier, in 1969–70, the club played in the Cup Winners' Cup, where it eliminated Denmark's Frem and was stopped by Levski Sofia.
For most of the twentieth century St. Gallen played at Espenmoos, which gave the club its nickname. In 2008 it moved to a modern stadium in the west of the city. Supporters behind one goal are known for their colourful displays, and St. Gallen is regarded as a city where football has an unusually strong standing by Swiss standards.
The club's history is a history of longevity: from a restaurant on Neugasse, through two league titles separated by almost a century, to a second Swiss Cup won in 2026. For supporters in eastern Switzerland, the oldest club in the country remains more than just a league side.