Micky Mellon has had his contract terminated as manager of Fleetwood Town "with immediate effect".
Fleetwood, who are currently in seventh place in the League Two table, were beaten 3-2 at home to Aldershot in the FA Cup on Saturday.
"The club would like to place on record our sincere appreciation for what he has achieved during his time with the club," read a statement.
Mellon took over at Highbury Stadium in 2008 and guided the team to the Football League last season.