IK SiriusIK Sirius was founded on 9 August 1907 in the Svartbäcken district of Uppsala, and according to the club's own history the founding took place in a ditch beside a sports ground. The founders, David Pettersson and Abdon Eklund, set up the club for athletics rather than football. For a few months it was discussed under the names Svartbäckens IK and IK Spurt, and on 5 April 1908 the members settled on Sirius. Football and bandy were added the same year, and over the decades the club also took up swimming, water polo, ice hockey, handball, bowling and skiing.
Bandy was in fact the club's first great sport. Sirius were Swedish bandy champions in 1921 and 1922 and won the title three more times in the 1960s, in 1961, 1966 and 1968, and they were runners-up in 1918, 1926, 1928, 1960 and 1962. This explains a common confusion about the club's history: the 1928 final in which Sirius finished as runners-up was played in bandy, not football. The home of both sports is Studenternas IP, which lies by the Fyris river in central Uppsala and holds about 10,000 spectators.
In football the club's greatest success of the early era came in 1924. After winning the Östsvenska Serien in 1923–24, Sirius reached the final of the Svenska Mästerskapet, the cup competition that decided the Swedish champions, and lost it 0–5 to Fässbergs IF. That final remains the club's only silver medal in the national championship, and the competition was played for the last time in 1925. The same season Sirius had been among the sides in contention for a place in the newly formed Allsvenskan, but the place went to Västerås IK.
The club then spent most of its history below the top flight. Sirius won Division II Svealand in 1968, eight points ahead of Hammarby, and then went through a promotion qualifier, beating Landskrona BoIS 1–0 and Sandvikens AIK 3–0 and losing 2–3 to Jönköpings Södra, which was enough to reach Allsvenskan. The first stay lasted a single season, and it was followed by relegation in 1969 with a 12th-place finish. Sirius returned in 1973 and played in the top flight again in 1974, and then went down to the fourth tier in the early 1980s, playing four seasons in Division 1 Norra between 2010 and 2013.
The modern rise began with an unbeaten promotion season in 2013 that took the club back to Superettan. In 2013–14 Sirius reached the semi-finals of the Svenska Cupen as a second-tier newcomer and were stopped by IF Elfsborg. In 2016 the club won Superettan and secured promotion in the 28th round with a 1–0 win away at Halmstads BK, with the goal scored by Jakob Bergman. It meant a first Allsvenskan season since 1974, after an absence of 42 years.
Since then Sirius has become an established Allsvenskan side. It finished 7th in 2017, 13th in 2018, 11th in 2019 and 9th of 16 in 2025, and in the 2026 season it is playing in the top flight for the tenth year in a row. The supporters call the club Blåsvart, the Blue-Black, and its story is one of persistence: a small athletics society from Svartbäcken, whose best moments came in bandy, and which found its place in Swedish football only in the last decade.