The Thessaloniki native, who spent his final years living in the USA, made history by taking the country to their first European Championship and World Cup campaigns
The man who led the country to their first major international tournament, Euro '80, and their first World Cup finals appearance, at USA '94, passed away at his Virginia home on Monday.
"Greek football mourns the loss of Alketas Panagoulias, who was a pioneer," the Hellenic Football Federation (HFF) said in a statement released on Tuesday. "This brings great sadness to the football family in our country."
The Thessaloniki native represented local club side Aris as a player before turning his hand to coaching with great success.
Panagoulias enjoyed unprecedented success with the country, either side of a two-year stint as USA boss and two separate spells in charge of Olympiakos, with whom he won three national titles.
The HFF has already confirmed that their players will wear black armbands in Friday night's quarter-final clash with Germany in honour of their former coach.