[2] After his retirement from playing at the end of the 1955–56 season, Crompton was hired as a trainer by Luton Town, before returning to Manchester United in the wake of the Munich air disaster two years later.
[3] Luton rehired him as their manager in 1962 as a replacement for the departing Sam Bartram, but his tenure lasted just seven days and he returned to his position at Manchester United.
[4] In 1971, Crompton was named as manager of Barrow, replacing Don McEvoy, but he only lasted until the end of the season and in June 1972, he was hired by Bury as a coach.
In 1973, Crompton joined Preston North End as part of fellow former Manchester United man Bobby Charlton's coaching staff.
[5] He was also president of Curzon Ashton, who in 2012 played in a friendly against a Manchester United reserve XI for the "Jack Crompton Trophy".