Sixty firefighters and 23 fire engines tackled the blazes, backed by six helicopters and seven planes.
By Sunday, all the fires were under control, the Fire Brigade said, while in Evia a 57-year-old man was arrested for arson.
According to ANA news agency, he is a farmer who told police that while trying to crank start his van, sparks from the exhaust set grass alight and burned through 400 hectares of vegetation.
The civil protection department issued a high risk warning of wildfires over Sunday.
Greece faces forest fires every summer, fanned by dry weather, strong winds as temperatures soar well above 30 degrees Celsius.
In 2018, 102 people died in the coastal resort of Mati, near Athens, in Greece's worst-ever fire disaster.
According to Kathimerini daily, 179 fires were caused by negligence and 26 deliberately set in 2020.