This paper provides an introduction to a special issue focusing on diverse examples of policy practice in social inclusion and ageing across different regions of the world. These examples illustrate the multifaceted nature of the concept of social inclusion, and how it is applied in the context of global demographic ageing. The paper begins with an exploration of the history and development of the concept of social inclusion, as applied to ageing policy, and how the concept has emerged following its initial association with economic disadvantage. Now commonly defined as relating to social participation in key activities of the society in which people live, a social inclusionary approach highlights the risks of social exclusion and isolation faced by older people. Social inclusion thus incorporates core issues in ageing such as civil engagement, an ageing workforce, age-friendly communities, and civic involvement. There are some particular challenges to implementing social inclusion policies within the current environment, which are addressed within this special issue, and these include the impact of social and cultural change, particularly across some of the East Asian countries, and the impact of global financial crises on work and retirement.