Saudi Arabia also called backed its ambassador from Ottawa and ordered Canada's chief envoy out of the country.
Canada's arms trade to Saudi Arabia, which is led by what is widely viewed as a deeply repressive regime, has raised numerous complaints from human rights and arms-control groups.
Canada annoyed Riyadh last week when it called for the "immediate release" of rights campaigners, including award-winning women's rights activist Samar Badawi, the sister of jailed blogger Raif Badawi.
Riyadh said that amounted to "blatant interference in the Kingdom's domestic affairs, against basic worldwide norms and all global protocols".
Niagara College was expecting 40 students from Saudi Arabia to arrive for the fall term.
The standoff pits a Saudi government that's slowly opening the door to women's rights against Canadian Prime Minister Justin Trudeau, an outspoken champion of women's advancement, who named a gender-balanced cabinet shortly after his 2015 election.
"We continue to encourage the government of Saudi Arabia to ensure all are afforded due process and to provide information on the charges and case status of legal actions against activists", the anonymous spokeswoman told AFP.
UAE Minister of State for Foreign Affairs Anwar Gargash said in a tweet on Monday that he stands with Saudi Arabia in "defending its sovereignty and laws".
The moves carried on the official Saudi Press Agency, caught diplomats in Riyadh off guard.
A state-run news organization is reporting the kingdom is cutting off scholarship and fellowship programs to about 15,000 students now taking classes in Canada.
It's a significant demand, with Saudi students making up the fourth-largest contingent of foreign students in the country.
"All Saudia flights from/to Toronto, Canada will be suspended starting from 13 Aug 2018", the airline wrote in a statement posted on Twitter.
The United Arab Emirates, Bahrain and Palestinian Authority have all come out in support of Saudi Arabia, as did Comoros, Djibouti and Mauritania. The Twitter account had been described as "an official government" account in Saudi-owned state media, although the relationship to the Saudi state was not clear. But his reforms include no changes that would liberalise a political system that allows no public dissent.
"Branding Saudi Arabia as an attractive destination for investment and trade is one of the underlying assumptions of Saudi Vision 2030", said Thomas Juneau, an assistant professor and Middle East expert at the University of Ottawa.
Riyadh has a record of responding robustly to Western criticism under Mohammed bin Salman.
Nauert stopped short of criticizing the detention of rights activists in Saudi Arabia.
On Monday, the Saudi foreign ministry tweeted: 'The kingdom announces that it is recalling its ambassador to Canada for consultation.
According to Reuters, Saudi-Canadian trade consists largely of Saudi exports of petrochemicals, plastics and other products.
If the Saudi government follows through on the decision, it's believed that many students in Canada will seek placement at universities in the United States and United Kingdom.