The 46-year-old Spaniard was appointed as Belgium manager in August 2016 and he led them to third place at the 2018 FIFA World Cup in Russia.
Martinez’s previous deal was due to expire after EURO 2020, but the tournament was postponed to next year by UEFA because of the Coronavirus pandemic, which has disrupted the footballing calendar.
Belgium, who currently top the FIFA world rankings, won all 10 of their EURO 2020 qualifiers and were one of the favourites going into the rearranged tournament, as they boast one of the most formidable squads in world football, with the likes of Eden Hazard, Kevin de Bruyne and Romelu Lukaku all available for selection.
"Because of the Euro 2020 postponement we could not possibly end our collaboration already now," Martinez said, in a statement released by Belgium.
"The RBFA has an ambitious plan that I look forward to with great enthusiasm, both in the short and long term.
"The next two and a half years will be very intense for our national team, with the European Championship, Nations League, 2020 World Cup qualifying matches and the World Cup in Qatar itself.
"I can only be happy and proud that I can continue working and prepare the future of Belgian football."
Martinez has previously spent time in England managing the likes of Swansea City, Everton and Wigan Athletic, a team he led to FA Cup glory in 2013.
