Fire swept through the village 40km (25 miles) north-east of Athens on Monday and was still burning in some areas on Tuesday.
Desperate families trying to reach the safety of the sea were trapped by walls of smoke and flame. Others died in buildings or cars.
After the 26 bodies were found in an open space, Nikos Economopoulos, head of Greece’s Red Cross, said: “They had tried to find an escape route but unfortunately these people and their kids didn’t make it in time. Instinctively, seeing the end nearing, they embraced.”
Dimitri Piros, director of medical services for Ekav, Greece’s nationwide ambulance service, told the BBC people had suffered horrific injuries because of the speed of the fire.
The blaze struck like a flamethrower, he said, causing both smoke inhalation and skin burns.
Coastal patrol boats and private vessels picked up hundreds of those who did manage to reach harbours or beaches.
“Thankfully the sea was there and we went into the sea, because the flames were chasing us all the way to the water,” said one survivor, Kostas Laganos.
“It burned our backs and we dived into the water… I said: ‘My God, we must run to save ourselves.'”
George Vokas, whose family escaped by sea but whose house and cars were burnt, told BBC News that two women he had tried to help had died.
“We’re talking about a biblical catastrophe in this wonderful area of Mati,” he said.
Charred bodies lay just 15m (50ft) from the sea, photographer Pantelis Saitas told the Athens-Macedonian News Agency. At least 150 people were injured in the area.