Within the domain of international law, states are bound by obligations to prevent and combat acts of terrorism and to refrain from any form of support or sponsorship of such crimes. A state that directly or indirectly engages in terrorist acts bears responsibility for its actions. Any provision of financial support for terrorism, whether direct or indirect, is prohibited under international conventions and entails state responsibility. The recognition of both civil and criminal international responsibility of a state that has supported the commission of a terrorist act can serve as an appropriate response to such crimes. This article examines the international responsibility of states in relation to terrorism and its financing. Employing a descriptive-analytical approach and drawing upon documents and written sources, the study has been conducted through library-based research. The findings indicate that with the expansion of state-sponsored terrorism and other international crimes—considering the significant damage and casualties they cause, the targeting of vital interests of states, and the threat they pose to international peace and security—most countries have come to acknowledge the necessity of adopting and implementing the theory of international criminal responsibility of states. They increasingly believe that the positive outcomes of applying this theory far outweigh its potential drawbacks. Moreover, combating international crimes cannot be fully achieved without recognizing the criminal responsibility of states, alongside the criminal liability of individual perpetrators.