Global developments in dual citizenship legislation highlight changes to conceptualizations of citizenship by increasing the focus on individual rights. Questions of inclusion and exclusion have been illuminated by the move toward wider acceptance of dual citizenship. To understand global patterns and developments in dual citizenship laws this article analyzes the legislation pertaining to dual citizenship in 115 countries. The results show how dual citizenship is becoming increasingly accepted – a development that has predominantly taken place within the last 20 years. A strong regional pattern is identified, supporting the argument that dual citizenship is spreading in a fashion similar to how the idea of citizenship expanded from Europe in the 19th and 20th centuries. Potential internal and external reasons for this development are discussed and individual countries’ experiences analyzed.