Firefighters were called to Aylesbury United’s former ground in Buckingham Road on Saturday evening.
The blaze broke out in the clubhouse beneath the football stand at around 5.55pm.
Four fire engines attended the incident which police say they are treating as arson.
The stadium has not been used since 2006 when the Ducks were evicted, with the buildings becoming derelict in the years since.
Aylesbury United currently play at Leighton Buzzard.