They are involved in a human rights row over Canada's demands for Canadian activists jailed in the kingdom to be released.
Saudi Arabia, enraged by what it said was meddling in its internal affairs, asked the Canadian ambassador to Riyadh to leave the country within 24 hours and recalled its envoy to Ottawa.
In response, Canada's foreign affairs minister Chrystia Freeland said the government will not back down.
"We are always going to speak up for human rights, we are always going to speak up for women's rights and that is not going to change", Freeland said.
The sudden and unexpected dispute bore the hallmarks of Crown Prince Mohammed bin Salman, Saudi Arabia's 32-year-old future leader, whose recent foreign policy exploits include the war in Yemen, the boycott of Qatar and Lebanese Prime Minister Saad Hariri's surprise resignation broadcast during a visit to the kingdom.
Saudi Arabia on Sunday expelled Canada's ambassador and said it would freeze new trade deals following a tweet by Global Affairs Canada criticizing the kingdom's arrests of human rights activists, including women's rights activists. Canadian exports to Saudi Arabia totaled about $1.12 billion in 2017, or 0.2 percent of the total value of Canadian exports.
Traders said they had received an official notice from the Saudi Grains Organization (SAGO) about its decision.
Saudi Arabia responded to the criticism with an array of sanctions that included suspending flights to Canada, expelling the Canadian ambassador, freezing all business between the two countries and terminating its student exchange program.
Saudi's foreign ministry called the statement "a major, unacceptable affront to the kingdom's laws and judicial process".
The Office of the UN High Commissioner for Human Rights estimates that at least 15 human rights defenders and women's rights activists critical of the Saudi government had been arrested or detained arbitrarily since 15 May. His wife, Ensaf Haidar, lives in Canada and recently became a Canadian citizen.
'It is now time for other governments to join Canada in increasing the pressure on Saudi Arabia to release all prisoners of conscience immediately and unconditionally, ' said Samah Hadid, Amnesty International's Middle East campaigns director.
Counting several Saudi diplomatic figures among its more than 350,000 followers, the now-deleted account is run by volunteers and managed by Saudi youth with an interest in technology and social media, according to an affiliated website.