Zakaria Amara, a Jordanian-born Canadian citizen, was sentenced on Monday "for his role in a terrorist plot to bomb Toronto", the public prosecution service of Canada said in a statement.
He was also sentenced to nine years "for his participation in a terrorist group," to be served concurrently.
The sentence is the stiffest punishment imposed in the conspiracy and under Canada's anti-terrorism laws, which parliament passed in the wake of the September 11 attacks on the United States in 2001.
But Amara may be eligible for parole in less than seven years after having already served time in prison awaiting trial.
Amara had pleaded guilty to involvement in the Toronto 18 plot to set off bombs outside Toronto's stock exchange, the country's spy agency and a military base.Judge Bruce Durno, who read out the sentence, said that if the plot been successful it would have been the most horrific crime in Canada's history.
"What this case revealed was spine-chilling,'' Durno said.
"Zakaria Amara did not just commit a criminal offence. He committed a terrorist offence that would have had catastrophic and fatal consequences."
After the judge read his sentencing Amara addressed him saying "I just want to reassure you that the promises I made [to rehabilitate], I'll do my best."
Michael Lacy, Amara's defence lawyer, said the defence was disappointed with the sentence in view of Amara's "genuine expressions of remorse and in light of his denunciation of the terrorist activity".
He said they had not decided whether to appeal.
The 2006 arrests of Amara and 17 other people made international headlines and heightened fears in Canada, where many people thought their country was relatively immune from attacks.
Prosecutors said Amara planned to rent trucks, pack them with explosives and detonate them via remote control.
Police found he used a public library computer to conduct searches on bomb-making and the chemicals needed for explosives.
A bomb-making manual, circuit boards, and a device that could trigger an explosion via a cell phone were found in his home.
Amara had tried to buy what he believed was three tons of ammonium nitrate from undercover police officers, who had switched it with an inert substance.
His personal computer also had recordings of Osama bin Laden, the al-Qaeda leader.
Also sentenced on Monday was Saad Gaya, one of Amara's suspected co-conspirators, who was given 12 years in prison, minus seven-and-a-half years credit for pre-trial custody.
Since the arrest of the Toronto 18, four have now pleaded guilty and one
Charges were stayed or dropped against seven people. One man's trial began last week and five others face trial in March.