The first involved a Vauxhall Insignia car which was accidentally set on fire at 10.15pm on Pastures Lanes in Cadeby.
Firefighters from the Dearne station attended the incident. They left at 11.05pm.
Later firefighters from Rotherham station were called out to a deliberate rubbish fire at 12.25am on Canklow Road in Canklow.
The crew returned to the station at 12.50am.
If you see a fire report it to 999.