The club, now in the Premier League, acted after the 21 were given football banning orders ranging from four to 10 years at a court hearing on Monday.
The fight happened after Burnley's Championship match against Sheffield Wednesday at Turf Moor in January 2014.
Nineteen fans were given jail terms of between five and 22 months for violent disorder at the town's Miners Club.
Those sentenced ranged from a 17-year-old boy to a man aged 54.
Furniture was broken and a window was smashed during the disorder at the club on Plumbe Street, which broke out around 18:00 GMT.
The football club's chief executive Lee Hoos said: "These people are clearly not fans and there is no place for them at Burnley Football Club."
Ch Supt Chris Bithell of Lancashire Police said: "The behaviour of all those involved in the disorder was disgraceful and completely unacceptable."
Burnley have handed out life bans to 21 fans who took part in a mass brawl with rival supporters after a match.