Small Island Developing States (SIDS) is a term that first appeared at the 1992 United NationsConference on Environment and Development (UNCED) to focus the attention of the international community on the unique characteristics and challenges of the small, ecologically fragile, and economically vulnerable island states. This note was prepared as a background document for the upcoming Third International Conference on SIDS, scheduled to take place in Samoa in September 2014. It aims to provide a quick overview of the main components of sustainable development financing in SIDS, based on numerical indicators and the latest available data. The note covers the following dimensions: heterogeneity of SIDS; domestic sources of financing; and external sources of financing. It does not provide policy recommendations.