The Canadian government designated the Proud Boys as a terrorist group on Wednesday after the pivotal role they played in the riot at the US Capitol on January 6.
The Proud Boys faced increased scrutiny after group members were major agitators in earlier protests and during the Capitol insurgency on January 6.
It is a far-right, male chauvinist extremist group known for violent clashes at political rallies. Canada is the first country to designate them as a terrorist entity.
During a September presidential debate, former president Donald Trump urged group members to "stand back and stand by" when asked by a moderator to condemn them.
Senior Canadian officials said authorities had been monitoring and collecting evidence about the Proud Boys before the Capitol insurrection.
But they confirmed that the event provided information that helped with the decision to list the organisation.
Public Safety Minister Bill Blair said the group had revealed itself through its actions at the event.
“Their intent and their escalation towards violence became quite clear,” Mr Blair said.
The terrorist designation means the group may have assets seized and face harsher terrorism-related criminal penalties.
A government official said being a member did not mean a person would be charged with a crime, but if that person engaged in violent acts it could lead to charges of terrorism.
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.
“The group regularly attends Black Lives Matter 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 government calls the group a neo-fascist organisation with semi-autonomous chapters in the US, Canada and other countries.
It said it engaged in political violence and that members espoused misogynistic, Islamophobic, anti-Semitic, anti-immigrant and white supremacist ideologies.
“Since 2018, we have seen an escalation towards violence for this group,” Mr Blair said.
“In the aftermath of the US presidential election, we have seen signals of escalation towards violence from a number of different groups, including the Proud Boys.”
He said four right-wing groups are among 13 additions to the list, which include three linked to Al Qaeda, four associated with ISIS and one Kashmiri organisation.
“Canada will not tolerate ideological, religious or politically motivated acts of violence,” Mr Blair said.
The Proud Boys were formed in 2016 by Canadian Gavin McInnes, who co-founded Vice Media.
In 2018, police arrested several members and associates who brawled with anti-fascist protesters after Mr McInnes delivered a speech at New York’s Metropolitan Republican Club.
He has described the group as a politically incorrect men’s club for “western chauvinists” and denies affiliations with far-right extremist groups that espouse racist and anti-Semitic views.
Mr McInnes sued the Southern Poverty Law Centre, claiming it defamed him when it designated the Proud Boys as a “hate group".
In response to the federal suit, which is still pending in Alabama, the law centre said Mr McInnes acknowledged an overlap between the Proud Boys and white nationalist groups.
“Indeed, Proud Boys members have posted social media pictures of themselves with prominent Holocaust deniers, white nationalists and known neo-Nazis,” law centre lawyers wrote in a court filing.
