The protest comes on the heels of last week's decision by the United Nations General Assembly to recognize Palestine as a non-member observer state.
Demonstrators who gathered in Montreal's Phillips Square said they were showing their solidarity and support for the people of Palestine.
"It's pretty clear that Canada is complicit with the occupation of Palestine and with the blockade of Gaza," said protestor Bader Takriti.
Last week, Canada voted against the bid to upgrade Palestine's status, along with eight other countries including Israel and the United Sates. A total of 138 nations voted in favour of the bid.
People attending the demonstration said they were ashamed of Canada's position.
"I don't think it's an exaggeration to state that Canadian foreign policy on the Middle East is dictated pretty much directly from Tel Aviv," said Bruce Katz, president of Palestinian and Jewish Unity and a member of the Coalition for Justice and Peace in Palestine.
He said that the UN's recent decision is important because it gives Palestine the right to present a case before the international criminal court.
The case could, according to Katz, accuse Israeli politicians of war crimes concerning the Gaza region.
Katz said it would also give Palestinians the right to add the name of Stephen Harper as complicit in those crimes.