The fire struck the resort of Mati and other seaside areas east of Athens on July 23, 2018, destroying more than a thousand homes. Some of the people who died were trapped by flames and others drowned in the sea while trying to escape thick smoke.
New Prime Minister Kyriakos Mitsotakis attended a memorial service in Mati earlier Tuesday.
"Today is a day of remembrance, one year after a national tragedy," government spokesman Stelios Petsas said, announcing tax relief measures for some 4,000 people who have so far failed to qualify for the benefit.
As residents of the fire-hit areas held a silent march in Mati Tuesday, fire crews battled a new blaze in the area, burning pine forest outside the port of Rafina.
Three planes and two helicopters dropped water, helping fire crews control the blaze that had threatened homes and forced the closure of a main road for several hours, blocking access to seaside areas popular with swimmers during the summer.