They were due to meet President Marcelo Rebelo de Sousa, who said he would honour them with an award for distinguished acts of public service.
"I have to praise everyone. I will commemorate them with the Order of Merit of Commanders - that is a decree that has never been given to the national team," he told broadcaster RTP.
The team were then expected to parade the trophy in the streets of Lisbon before addressing delirious supporters at the fanzone in the capital after the country erupted into noisy jubilation late on Sunday.
Former Portugal coach Luiz Felipe Scolari, who lost to Greece in the 2004 final hosted by Portugal, showered praise on the players.
"Portugal had deserved this European champion title since 2004. Last night, Portugal was able to get back the title that we lost in 2004," he told Sport TV.
(Reporting by Adriana Garcia; Editing by Alison Williams)
