The prohibition of torture is considered as a general principle of international law; States are obliged to respect this right and prevent infringing it. Throughout this paper, the concept of torture in an international context will be highlighted, stressing the main branches and instruments of international law that deals with torture, to at the end conclude a common definition. In the Introduction, a brief history of torture with different definitions and how it changed from being ordered by courts to being subject to an absolute prohibition will be provided. In Chapter 2, the concept of torture as a jus cogens will be outlined, going through the absolute non-derogable right of not being subject to torture; under human rights instruments such as the UDHR and the ICCPR. In addition, presenting torture under International Humanitarian Law, specifically under the Geneva Conventions and their Additional Protocols as a war crime. While also discussing the crime of torture under international criminal law as a crime against humanity and how the case law of the Nuremberg Trials, ICTY, and the ICTR contributed in shaping the legal framework of the prohibition. Chapter 3 will be dedicated to the United Nations Convention Against Torture as it is the specialized convention on torture. A thorough discussion will be presented on Article 1 that outlines the elements of the crime of torture and Article 2, that serves as the “Umbrella Clause” to the obligations of State parties of the Convention, in addition to setting the absolute non-derogable prohibition of torture. Chapter 4 will present the conclusions of this paper, and how the concept of torture differs under the UNCAT from other branches of international law. To at the end, present a concluded definition of torture that avoids ambiguity and arguments that try to derogate from this right. Going through these subjects, landmark judgments from international tribunals that helped ensuring the right not to be subject to torture will be highlighted, in addition to other international legal instruments. The travaux preparatoires of the UNCAT is very important to go through, it will help the reader stand at the position the drafters wanted from the Convention, and to avoid any misinterpretation of its provisions. Next to going through the General Comments issued by UN specialized bodies on relevant provisions when available, case law, and literature of specialized scholars in the field.