The Inter City Firm is an English

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 football hooligan

Football hooliganism

Football hooliganism, sometimes referred to by the British media as the English Disease, is unruly and destructive behaviour—such as brawls, vandalism and intimidation—by association football club fans...

 firm mainly active in the 1970s, 1980s and early 1990s, associated with West Ham United

West Ham United F.C.

West Ham United Football Club is an English professional football club based in Upton Park, Newham, East London. They play in The Football League Championship. The club was founded in 1895 as Thames Ironworks FC and reformed in 1900 as West Ham United. In 1904 the club relocated to their current...

. The name came from the use of InterCity

InterCity (British Rail)

InterCity was introduced by British Rail in 1966 as a brand-name for its long-haul express passenger services ....

 trains used to travel to away games. The ICF was still active as of 2009.
One figure associated with the ICF was Cass Pennant

Cass Pennant

Carol "Cass" Pennant , is an English writer and former football hooligan.-Background:Pennant's mother emigrated from Jamaica while pregnant and he was born in Doncaster, South Yorkshire. Six weeks old, he was abandoned and was placed into a Dr. Barnardo's Home...

, who wrote on football hooliganism in the 1990s and 2000s. He is the subject of the film Cass, which was released on 1 August 2008.