The RCMP said Friday the charge followed an investigation that alleges Mouna Diab committed offences for the benefit of a contact linked to Hezbollah.
Hezbollah has been considered a terrorist organization by Canada since December 2002.
Diab appeared briefly in court to be formally charged, the federal police force said.
Diab, 26, was arrested in May 2011 at Montreal's Pierre Elliott Trudeau International Airport for allegedly trying to smuggle parts for an AR-15 rifle in her luggage.
She was charged last October with illegally exporting weapons to Lebanon. A United Nations resolution prohibits Canadians from selling arms to anyone in Lebanon.
That charge, under the UN resolution, carries a maximum 10-year sentence.
A deeper investigation by the Integrated National Security Enforcement Team's Quebec branch brought about an alleged connection to Hezbollah and a new charge: committing an offence for a terrorist group, a charge that carries a maximum sentence of life in prison.
"It is alleged that Diab was acting under the direction of a contact person in Lebanon who is associated with Hezbollah," the RCMP said in a statement.
The RCMP alleges Diab was shipping parts through other Lebanese community members, although those people were unaware of what they were carrying.
The RCMP issued a warning Friday for travellers to be aware they can face charges if they are caught with illegal items. The force cautioned people not to carry packages on behalf of a third party if the contents are unknown.
Cpl. Carine Cordey said Diab appeared in court on Friday with the new charge and was not detained.
A former community activist, Diab was in the news at the height of Quebec's debate on reasonable accommodation of minorities.
She was one of a delegation of women who went to Herouxville, Que. to meet with the townspeople in 2007.
In Ottawa, Public Safety Minister Vic Toews applauded the RCMP announcement.
"The threat of terrorism around the world and here in Canada remains real and multi-faceted," Toews said in a statement, adding that strong police work is ensuring that Canada is not the source of weapons for terrorist groups.