Over the past decade, the amount and variety of addiction research around the world has increased substantially. Researchers in Australia, Canada, United Kingdom, United States, and western Europe have significantly contributed to knowledge about addiction and its treatment. However, the nature and context of substance use disorders and the populations using drugs are far more diverse than is reflected in studies done in Western cultures. To stimulate new research from a diverse set of cultural perspectives, the National Institute on Drug Abuse (NIDA) has promoted the development of addiction research capacity and skills around the world for over 25 years. This review will describe the programs NIDA has developed to sponsor international research and research fellows and will provide some examples of the work NIDA has supported. NIDA fellowships have allowed 496 individuals from 96 countries to be trained in addiction research. The United Arab Emirates and Saudi Arabia have recently developed funding to support addiction research to study, with advice from NIDA, the substance use disorder problems that affect their societies. Examples from Malaysia, Tanzania, Brazil, Russian Federation, Ukraine, Republic of Georgia, Iceland, China, and Vietnam are used to illustrate research being conducted with NIDA support. Health services research, collaboratively funded by the U.S. National Institutes of Health and Department of State, addresses a range of addiction service development questions in low- and middle-income countries. Findings have expanded the understanding of addiction and its treatment, and are enhancing the ability of practitioners and policy makers to address substance use disorders.