The Canadian government has designated the Proud Boys as a terrorist entity, saying the group played a pivotal role in the riot at the US Capitol on 6 January.
The Proud Boys is a male chauvinist extremist group known for engaging in violent clashes at political rallies.
Canada is the first country to designate them as a terrorist entity.
The terrorist designation means the group may have assets seized and face harsher terrorism-related criminal penalties.
A government official said just because they are a member doesn't mean they will be charged with a crime but if they do engage in violent acts they could be charged with terrorist crimes.
Sending money to the organisation or buying Proud Boys paraphernalia would also be a crime.
"The group and its members have openly encouraged, planned, and conducted violent activities against those they perceive to be opposed to their ideology and political beliefs," the Canadian government said in briefing materials.
"The group regularly attends Black Lives Matter (BLM) protests as counter-protesters, often engaging in violence targeting BLM supporters. On January 6, 2021, the Proud Boys played a pivotal role in the insurrection at the US Capitol."
The Canadian government calls the Proud Boys a neo-fascist organisation with semi-autonomous chapters located in the United States, Canada and internationally.
It said it engages in political violence and that members espouse misogynistic, Islamophobic, anti-Semitic, anti-immigrant and white supremacist ideologies.
Public Safety Minister Bill Blair said 12 other groups, including five affiliated with the Islamic State, were also added to the list on Wednesday.
"Canada will not tolerate ideological, religious or politically motivated acts of violence," Mr Blair said.
With the new additions, there are now 73 terrorist entities listed under the country's criminal code.
