IK Oskarshamn (abbreviated as IKO) was founded in 1970 when the town's two then existing ice hockey teams, Oskarshamns AIK and IFK Oskarshamn, were merged into one. The team has twice reached the final qualification stage for the highest league in Sweden. This happened in the 2000–01 season and in the 2004–05 season. The team play their home games in Arena Oskarshamn which has a capacity of 3,424 people. The arena was first built in 1974 but was completely renovated and enlarged in 2005.
In the 2000–01 season and in the 2004–05 season IK Oskarshamn succeeded to reach the Kvalserien. In Kvalserien the team finished in 5th place the first year and in 6th place the second year. In the 2010–11 season IK Oskarshamn finished 9th in Hockeyallsvenskan, six points from playing in the new pre-qualification. Both in 2011-12 season and in 2012-13 season IK Oskarshamn finished topp-7 and reached the Playoff round. IK Oskarshamns Evan McGrath was the top scorer in the HockeyAllsvenskan regular season with 50 points in 52 games.