Alqunun had been on vacation with her family in Kuwait earlier this month when she ran away and took a flight to Bangkok, NPR reports.
"I understand that there have been death threats against her but I don't know the details", said Phil Robertson from Human Rights Watch, adding even threats from online trolls need to be taken seriously.
Canadian Prime Minister Justin Trudeau earlier told reporters that his country had granted a request from the United Nations High Commissioner for Refugees to grant asylum. Riyadh expelled Canada's ambassador a year ago and recalled its own top diplomat in Ottawa after Canadian Foreign Minister Chrystia Freeland criticized the jailing of two Saudi women activists.
Last year, Freeland, who welcomed Qunun in Toronto, had called for the Saudi authorities to immediately release detained Saudi women's rights activists.
"She said that as soon as she arrives in Canada, the first thing she will do is to learn the language". She has claimed that she faced abuse at home, and feared punishment because she had denounced Islam.
She had meant to fly on to Australia, but barricaded herself in a hotel room in Bangkok's main airport on Sunday after Thai immigration officials attempted to deport her back to the Middle East.
But, armed with a smartphone and a hastily opened Twitter account, she forced a U-turn from Thai immigration police who handed her into the care of the United Nations' refugee agency as the #SaveRahaf hashtag case bounced across the world.
Alqunun, fresh off a flight from Seoul, South Korea, and sporting a grey "Canada" hoodie and a blue hat emblazened with the logo of the organization that arranged her resttlement, smiled and waved at a group of reporters, but offered no comment on her arrival.
The Saudi teenager who fled her "abusive" family to seek asylum overseas has arrived in Canada.More news: Saudi Arabian women to notified of divorce by SMS
"She is safe, and she is in good health, and good mental health".
In her last tweet before leaving for Toronto, Qunun said, "I did it", and posted pictures from inside an airplane.
Alqunun's plight captured global attention, especially since Saudi Arabia recently faced condemnation for the murder of dissident journalist Jamal Khashoggi - an event that put the country's human rights record under scrutiny.
A Saudi envoy in Bangkok denied any official Saudi involvement in Ms Qunun's detention, and her passport was later returned. She has refused to see her father who travelled to Thailand and expressed opposition to her resettlement.
Canada's move is sure to further strain its relations with the Arab kingdom.
"I survived from death", she said, reflecting that since the killing of journalist Jamal Khashoggi in a Saudi consulate in Instabul she has feared for her own life.
Australia's Foreign Minister Marise Payne met with senior Thai officials in Bangkok on Thursday.