An internationally known human rights advocate, Fr Drinan was the first - and only - Catholic priest to serve as a voting member of Congress, NBC News reports.
Georgetown University, where Fr Drinan lived, said that he had suffered from pneumonia and congestive heart failure during the previous 10 days.
Georgetown Rector, Fr John Langan, said "his death was peaceful, and he was surrounded by his family."
According to the Catholic News Agency, Fr Drinan ran for office in 1970 on anti-war platform, over the objections of his superiors.
The priest, who urged the Catholic Church to condemn the Vietnam War as "morally objectionable", was said to consider politics a natural extension of his work in public affairs and human rights. He also opposed the draft.
He was the first member of Congress to call for the impeachment of Richard Nixon in view of the administration's bombing of Cambodia.
However, Fr Drinan was also controversial for speaking and voting in favour of access to abortion. In 1996 he also spoke in support of President Bill Clinton's veto of the partial birth abortion ban.
Fr Drinan left office in 1980, after Pope John Paul II issued a directive barring priests from holding public office.
However, he continued his activism and served as President of Americans for Democratic Action, giving speeches nationwide on hunger, civil liberties, and the arms race.
Prior to his political career, Fr Drinan was the dean of the Boston College Law School from 1956 to 1970. During the 1960s, he called for the desegregation of public schools and urged students to become involved in civil rights.
In the 1990s, the priest testified against the impeachment of Clinton, saying that impeachment should be for an official act, not a private one.
First Roman Catholic Priest Elected To Congress Dies (NBC News, 29/1/07)
Priest-politician who supported abortion dies at 86 (Catholic News Agency, 29/1/07)
Father Drinan, lawmaker who defied Rome, dead at 86 (Catholic World News, 29/1/07)
LINKS (not necessarily endorsed by Church Resources)
Robert Drinan (Wikipedia)
Robert Drinan articles (Findarticles)
30 Jan 2007