IF Elfsborg

Idrottsföreningen Elfsborg, popularly known as IF Elfsborg, is a professional football club based in Borås, Sweden, and is affiliated with the Västergötland Football Association, one of the 24 federations that make up the Swedish Football Association. The team plays in the Allsvenskan and has spent most of its history in the top tier of Swedish football. Elfsborg plays its home matches at the Borås Arena, where it has played since 17 April 2005.

The club was founded in 1904 by a group of 19 young men. Borås Fotbollslag was formed at Ordenshuset in Landala (today Knalleland) on 26 June 1904. Its founder, the athlete Carl Larson, created the team because the city's main sports club, Borås Athletic, did not include football in its programme. In 1906 the club was renamed Riksidrottsförbundet because of the large number of teams using the name of the city of Borås, and subsequently took its current name, IF Elfsborg. The name derives from the province of Älvsborg, whose name it changed using the old spelling with an "E". The club's colours, which are reflected in its crest and kit — yellow and black — have the same origin. The colours, taken by Elfsborg from the Älvsborg regiment, represent not only the city but an entire region. A recurring club motto is Vi Tillsammans ("We together").

The Borås Arena is also informally known as the "Fortress of Elfsborg", since the team is one of the strongest at home in the Allsvenskan in the 2000s. It is also the only team in the Allsvenskan to have beaten the national team, 2–1 at the opening ceremony of the Ryavallen, and one of only two teams to win the Allsvenskan as a newly promoted side, in 1961. Elfsborg has taken part on several occasions in the qualifying rounds of the Champions League and in the UEFA Europa League, and was one of the winners of the UEFA Intertoto Cup in 2008. The club has won six national championships, the most recent in 2012, and two Swedish cups.