The then ICJ Judge Awn Shawkat Al-Khasawneh defined immunity “[as] … an exception from the general rule that man is responsible legally and morally for his actions.”1 While it is widely acknowledged that serving high-ranking public officials enjoy immunity from the jurisdiction of foreign courts in most circumstances, there is an ongoing debate regarding how far the immunity entitlement extends and whether there are exceptions to it, particularly in cases of serious criminal wrongs. The present chapter reviews the conceptual, doctrinal, and theoretical foundations of the immunities of foreign officials, and their subjective, material, and temporal scopes. It also examines the rules that govern situations when foreign official immunity may not apply or may apply only to official acts, and the conditions for either of these outcomes. The chapter draws from recent developments in international criminal law, international human rights law, and transnational criminal law, and builds on the influential contribution of the ILC on the topic “Immunity of State Officials from Foreign Criminal Jurisdiction” included in the long-term program of work of the commission in 2006.