IK Sirius, more commonly known simply as Sirius, is a Swedish football club located in Uppsala. The club is affiliated to the Upplands Fotbollforbund.
The club was formed in 1907, with its first success coming in 1924 when they reached the Svenska Masterskapet final (not to be confused with Svenska Serien, which never acquired an official status of deciding the Swedish Champions). In the final, they were trounced 5–0 by Fassbergs IF.
The Allsvenskan years
The club spent the next forty years in lower division anonymity, before favourable economic circumstances enabled them to gain promotion to Allsvenskan in 1968, although they were relegated after just one season. The high point was arguably in the years 1973–1974, when the club again gained promotion to the highest league and its squad contained a number of high-profile players, such as Roland Grip, then a member of the Swedish national team.
Obscurity and comeback
After the club's relegation from Allsvenskan in 1974, the club played in the second division until they plummeted to fourth division level following a couple of hard years in the beginning of the 1980s.