Under Canadian law what is considered to be treason?

Under Canada’s Criminal Code, treason is split into high treason and treason. Both concern attacks on Canada’s sovereignty, government, or defence—not ordinary political criticism, protest, or advocacy.^[1]

High treason

A person commits high treason who, in Canada:

• Kills or attempts to kill the reigning monarch, or inflicts serious bodily harm, maims, wounds, imprisons, or restrains them.
• Levies war against Canada, or does any act preparatory to levying such war.
• Assists an enemy at war with Canada, or armed forces against whom Canadian Forces are engaged in hostilities—even if Canada and that force’s country are not formally at war.^[1]

Canadian citizens and people who owe allegiance to the Crown in right of Canada can commit high treason by doing any of these acts inside or outside Canada.^[1]

Treason

A person commits treason who, in Canada:

• Uses force or violence to overthrow the federal government or a provincial government.
• Without lawful authority, gives a foreign state’s agent military or scientific information—or related sketches, plans, models, articles, notes, or documents—that they know or ought to know could be used to harm Canada’s safety or defence.
• Conspires to commit high treason or the forcible-overthrow offence.
• Forms an intention to commit high treason or forcibly overthrow government, and takes an overt act toward it.
• Conspires to give prohibited military or scientific information to a foreign state, or intends to do so and takes an overt act.^[1]

Again, Canadians and others owing allegiance to Canada can be prosecuted for these acts committed abroad.^[1]

Penalties

Offence	Maximum penalty
High treason	Life imprisonment [2]
Treason by force/violence to overthrow government; conspiracy or overt act toward high treason	Life imprisonment [2]
Treason involving prohibited military/scientific information during a state of war	Life imprisonment [2]
Same information offence during peacetime	Up to 14 years’ imprisonment [2]

Important distinction

Merely meeting foreign officials, expressing separatist views, criticizing the government, or advocating constitutional change is not automatically treason. The Code requires force or violence aimed at overthrowing government, unauthorized disclosure of defence-related information, war-related assistance, or a concrete overt act/conspiracy—not simply disloyal speech or political association.^[3][1]

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• https://lois-laws.justice.gc.ca/eng/acts/C-46/section-46.html      
• https://laws-lois.justice.gc.ca/eng/acts/c-46/page-5.html    
• https://halifax.citynews.ca/2026/01/29/experts-say-treason-definition-depends-if-youre-holding-criminal-code-or-dictionary/ 
• https://laws-lois.justice.gc.ca/eng/acts/c-46/section-582.html 
• https://en.wikipedia.org/wiki/Treason 
• https://canadacommons.ca/topics/treason/