AThe fire was discovered at Firth Park Academy, Firth Park, at 6.05am yesterday.
Firefighters said it was in the roof area of the sports hall.
They spent around 90 minutes at the scene.
The school has not yet confirmed the extent of the damage.
In the early hours of this morning firefighters dealt with a Volkswagen Golf set alight in Creswick Road, East Herringthorpe, Rotherham.
And last night a wheelie bin was torched outside a bungalow in Sunny Bank, High Green, Sheffield. The flames spread to the window frames of the property.
Firefighters were also called out yesterday to a vehicle set alight in Hollow Gate, Cadeby, Doncaster; fencing and grass found burning in Carlton Park, Carlton, Barnsley; grass on fire in Yews Lane, Kendray, Barnsley and a vehicle torched in Ings Road, Bentley, Doncaster.
Yesterday afternoon crews spent two hours tackling a blaze in the open in Park Spring Road, Grimethorpe, Barnsley and earlier in the day rubbish was set alight near allotments in Rodger Street, Thornhill, Rotherham.
On Saturday night a derelict building in College Lane, Rotherham town centre, was set alight and some grass was found burning in Bolton Road, Wath-upon-Dearne, Roitherham.
In the early hours of Saturday, a Ford Transit van was torched in Grange Road, Royston, Barnsley.
Anyone with information should call South Yorkshire Police on 101.