Firefighters were called out to HMP La Moye on Saturday night to tackle a blaze in the prison kitchen.
Prison staff called 999 shortly after 8pm, and all the emergency services were dispatched as a precaution.
The fire was put out a short time later.
No one was injured during the incident, and the Prison Service says there is 'no suggestion' of any suspicious activity or the fire being started deliberately.
Contingency plans have been brought in to make sure prisoners are being fed as normal.

St Saviour break and entry suspect pictured posing on motorbike
'Overstretched' neurology department following under-experienced managers
Channel Islanders asked to report injured or dead seabirds
'Concerning' e-bike rider not stopping for police
Scottish man (27) jailed for smuggling £17,500 worth of cocaine to Jersey
'Jersey Lifts' drivers could be fined £10,000
Railway Walk still closed and 'extremely unsafe'
3 in 4 Jersey cats not microchipped or registered incorrectly