Father Gravel, 61, died of lung cancer Aug. 11. He was well known for publicly questioning church teachings on homosexuality, abortion and the role of women in the church and had served in Canada's House of Commons.
Government officials and firefighters were among those in attendance at the Aug. 15 funeral.
The homily was given by Father Pierre Gervais Majeau who, in a written tribute on Father Gravel's website, referred to his "capacity of indignation, a characteristic of prophets and those who bother people's consciences."
Before the ceremony, numerous laypeople paid homage to the priest, praising him for being "close to the people" and daring to speak out.
"Raymond said out loud the things that many Quebecers thought but didn't dare express," said Radio Canada journalist Alain Crevier, a longtime friend.
As reactions of sadness and support for Father Gravel flowed on Twitter and Internet forums, Montreal Mayor Denis Coderre described the priest as "an inspiring human being, with great dignity." He announced that the Montreal city flag was flown at half-staff the evening of Aug. 11 in honor of Father Gravel.
Quebec Premier Philippe Couillard described Father Gravel as "a man of conviction who has left his mark on thousands of Quebecers."
Born in rural Quebec in 1952, the young Raymond Gravel ran into drugs and prostitution in the bars of Montreal's Gay Village. He later turned away from his past and was ordained a priest in 1986, becoming parish priest in Joliette, north of Montreal. An outspoken supporter of gay and women's rights, he made it a part of his ministry to celebrate Mass at St. Peter the Apostle Church, where members of Montreal's gay and lesbian community worshipped.
A strong believer in Quebec's independence, Father Gravel was elected to a seat in the House of Commons as a member of the separatist Bloc Quebecois party in 2006 with the permission of his bishop. He left politics in 2008 when Vatican authorities told him to choose between his priesthood or a political career.
After his cancer diagnosis, Father Gravel appeared on a Montreal talk show on which he said he found it comforting to know that a euthanasia bill was being debated by the Quebec Parliament. The bill, which was strongly opposed by Quebec's bishops, became law June 5.
Father Gravel was also the chaplain of the Montreal firefighters, as well as those of Mascouche, a rural town north of Montreal. On July 14, Father Gravel made one of his last public appearances, attending the inaugural ceremony for the new building that the Mascouche firefighters named in his honor.