On July 13, 2023, the International Court of Justice (ICJ) delivered its judgment in the case concerning Question of the Delimitation of the Continental Shelf Between Nicaragua and Colombia Beyond 200 Nautical Miles from the Nicaraguan Coast (Nicaragua v. Colombia) (2023 Judgment). This is the first decision addressing the question of the delimitation of the continental shelf, between states with opposite coasts, in a situation where one state asserts a continental shelf extending beyond 200 nautical miles (extended continental shelf) within the 200 miles from the baselines of another state.

On July 18, 2023, the Appeals Chamber, by a 3–2 majority, rendered its “Judgment on the appeal of the Republic of the Philippines against Pre-Trial Chamber I's ‘Authorisation pursuant to article 18(2) of the Statute to resume the investigation.’” The decision upheld the Pre-Trial Chamber's decision of January 26, 2023, which authorized the Prosecutor to resume investigating crimes within the jurisdiction of the Court allegedly committed on the territory of the Philippines between November 1, 2011 and March 16, 2019, in the context of a government-led “war on drugs” campaign.

In its 75th ordinary session, the African Commission on Human and Peoples’ Rights (ACHPR, or Commission), the human rights organ of the African Union, with a mandate to promote and protect human and peoples’ rights and interpret the African Charter on Human and Peoples’ Rights, unanimously adopted the African Guiding Principles on the Human Rights of Migrants, Refugees and Asylum Seekers (Guiding Principles). They were publicly launched by the Commission at its 77th ordinary session on October 21, 2023. The drafting was led by the Commission's Special Rapporteur on Refugees, Asylum Seekers, Internally Displaced Persons, and Migrants in Africa. The thirty-eight Guiding Principles are based largely on African regional treaty law, case law, standards, and resolutions of the Commission and also draw from complementary international law. In addition, the Guiding Principles draw from the experience of other world regions, including adoption by the Inter-American Commission on Human Rights (the human rights organ of the Organization for American States) of the 2019 Inter-American Principles on the Human Rights of All Migrants, Refugees, Stateless Persons, and Victims of Human Trafficking.

On December 19, 2023, the Svea Court of Appeal in Sweden issued its judgment in the above case affirming the conviction and sentencing of Hossein Seyed Ahmadi, an Iranian citizen, for grave breaches of international humanitarian law and murder that took place in Iran in 1988. Specifically, he was charged with having executed prisoners associated with the People's Mojahedin Organization of Iran in the Gohardasht prison. Though the Court of Appeal dismissed the conviction of grave breaches of IHL with regard to some of the prisoners at issue, it found overall that the district court was correct in holding that the prosecutor substantiated the charges levied against Ahmadi. With regard to the murder charge, the Court of Appeal affirmed and noted that it should actually have been considered several acts of murder instead of just one single act. One judge dissented and argued that the defendant should have been found guilty of aiding and abetting murder rather than murder itself. The Court of Appeal also agreed with the district court's assessment that the acts took place in relation to the conflict between Iran and Iraq, thus triggering the application of IHL. Ahmadi's sentence to life in prison stands, and damages have been awarded to surviving plaintiffs and relatives of the deceased prisoners.