Marín, who since 2008 was the chairman of Fundacion Iberdrola Spain, the charitable arm of the country's largest power company, passed away in Madrid after "after a long illness", Iberdrola said in a statement. Spanish media said he had cancer.
As Spain's secretary of state for relations with European communities in the 1980s, he led succesful negotiations to enter the European Community (EC), the precursor to the European Union.
He went on to occupy a number of senior posts in the European Commission, the executive arm of the EU, between 1986 -- the year Spain joined the bloc -- and 1999, including vice president and commissioner in charge of eduction.
Under his watch as education commissioner, the bloc in 1987 set up and implemented its Erasmus student exchange scheme which helps university students follow some of their studies in other EU countries.
Over nine million people have taken part in the programme, named after the Dutch philosopher Desiderius Erasmus (1466 - 1536), who travelled around Europe during the Renaissance to further humanist thinking.
"Very sad about the death of my friend Manuel Marín, former Spanish commissioner and father of the Erasmus programme," European Commission President Jean-Claude Juncker wrote in a Twitter message.
Spanish Foreign Minister Alfonso Dastis hailed Marín as a "great Europeanist" while Spain's parliament speaker Ana Pastor called him a "gentleman of politics".
Marín, who served as speaker of the Spanish parliament himself between 2004 and 2008, was married and had two daughters.