Officials said the charred body of a 40-year-old man was found at the foot of Mount Parnis, which has a thickly forested national park.
The cause of the fire was not immediately known, but past summer wildfires in Greece have been blamed on extremely dry brush and land developers seeking to take advantage of laws that allow construction on burned land.
More than a dozen houses were destroyed by the fire, which was pushed by strong winds toward the suburbs of Acharnes and Thrakomakedones, about 15 kilometers (nine miles) north of central Athens. Police ordered widespread evacuations of the suburbs, home to more than 40,000 people.
The front of the fire was about four kilometers (2 1/2 miles) from the newly built Olympic Village, which will house 16,000 athletes and officials during the Aug. 13-29 Games.
``We are facing a very difficult situation,'' deputy fire chief Andreas Kois said. ``We are facing very strong winds and many sources of fire. We are working in dangerous conditions. We are using all the means at our disposal and are fighting it from land and air.''
More than 200 firefighters, dozens of fire trucks, six special planes and five helicopters were called in to try to slow the fast-moving walls of flames, officials said.
Deputy Interior Minister Athanassios Nakos said he was confident the fire would be brought under control by nightfall.
The fire was the second in as many days. Earlier this week the Greek civil defense agency warned that conditions were ideal for blazes in Athens and parts of central Greece.
Such alerts are normal for Greece in July, when temperatures soar and hot southerly winds often blow over from the Sahara desert in North Africa.
The National Weather Service said the temperature in Athens was 36 degrees Celsius (97 degrees F) and winds exceeded 61 kilometers per hour (38 mph), a moderate gale. Similar conditions were forecast for Thursday.
There have been fears that the large number of firefighters, police officers and soldiers needed to safeguard the Olympics could detract from Greece's ability to battle seasonal wildfires.
