The purpose of this thesis is to examine the Canada-United States Safe Third Country Agreement (hereinafter the "STCA"). In the wake of Donald Trump's election as US president, the executive orders he has issued on matters of immigration, and various policies implemented by the administration, it is worth questioning the STCA and its relevance. The STCA is an agreement between Canada and the United States that outlines how refugee claimants are to be addressed by these two countries. The agreement came into effect in 2004. It requires refugee claimants to request refugee protection in the first safe country in which they arrive in, unless they qualify for an exception to the agreement. 1 Various organizations, including the Canadian Council for Refugees (hereinafter "CCR"), and the Canadian Association of Refugee Lawyers (CARL) have called for the suspension of the STCA, on the grounds that the United States is no longer a safe country, following President Trump's executive orders and the influx of asylum-seekers crossing the border into Canada. The number of asylum-seekers has dramatically increased since January 2017, with an estimated 32,000 having arrived in Canada in 2017 alone. The STCA violates both international and domestic law. Specifically, the STCA violates the 1951 Convention Relating to the Status of Refugees (hereinafter "the Refugee Convention") and the 1967 Protocol Relating to the Status of Refugees (hereinafter "the 1967 Protocol"). Domestically, it is in violation of the Canadian Charter or Rights and Freedoms (hereinafter "the Charter"). This thesis concludes that the cornerstone of the Convention, the principle of non-1 Agreement between the Government of Canada and the Government of the United States of America for cooperation in the examination of refugee status claims for nationals of third countries, Canada and the United States of America, 5 December 2002, Treaty Law Division (entered into force 29 December 2004). refoulement, has achieved the status of jus cogens, that is, a norm of international law from which no derogation is permitted. 2 First and foremost, I would like to extent my sincerest gratitude to my thesis supervisor Professor Umut Ozsu. Thank you for your guidance and the patience you have shown me as I have undertaken the most significant project of my life to date. This thesis is your accomplishment as much as it is mine. I have been extremely fortunate to have had a supervisor as compassionate and caring as you, who has responded to my questions so promptly. Thank you from the bottom of my heart. To Randy and Richard, thank you for your continuous support throughout my academic journey. This accomplishment would not have been possible without you. I will forever be indebted to you for your encouragement, your patience, and most of all, your unshaken support. Throughout the last few years, you two have been the only constant in my life, and my family away from home. Thank you! To my best friend, Saranda Shala, who has read every draft of this thesis and offered her inval...