It was founded on May 25, 1905 under the name Lyn, and changed its name to IF Pors in 1914 because the original name was already in use. Since 1994 the name has been Pors Grenland. The best performances of the team was in 1948–49 and 1970 when they played in the top division. The team has had unsuccessful bids for promotion to the premier division in 1972, 1979, 1981 and 1983. Until 1999 Pors Grenland was the only Telemark team to have reached the premier division.
Concurrent with the 1994 name change the club entered into a still ongoing elite-level athletics partnership with the other and dominant Grenland football club, Odd Grenland. In February 2005 IF Pors retained other sports activities whereas Pors Grenland Fotball was siphoned off as a separate sports team, however still under the auspices of IF Pors. In December 2009, the financial cooperation between Pors Grenland and Odd Grenland was terminated.