Both the opposition New Democrats and Liberals voted against it, saying they fear the mission could become a quagmire.
Six hundred air crew and other personnel, along with six fighter jets and several other military aircraft, will now head to the Middle East.
Harper has ruled out sending ground combat troops.
But 69 special forces soldiers already on the ground will continue to advise security forces fighting the Islamic State group in the northern part of Iraq.
The Islamic State group gained international attention in August, when its fighters and those from other militant groups swept through the northern Iraqi city of Mosul, then overran swaths of territory north and west of Baghdad.
Western governments fear IS could eventually strike overseas, but their biggest worry for now is its gains in Iraq.
US President Barack Obama last month outlined plans for a broad international coalition to defeat the group in Iraq and Syria.
The coalition, which includes Arab countries, intends to "significantly degrade the capabilities of ISIL, specifically its ability to engage in military movements of scale or to operate bases in the open," Harper said on Friday, using an alternate acronym for the group.
The military mission is supported by 64 percent of Canadians, according to a poll published by the daily Globe and Mail.