If development is about poverty reduction, where the poorest live is an important question, especially so amid policy debates on what might follow the UN Millennium Development Goals. It is now well known that most of the poor do not live in low income nor fragile states, whether one uses income poverty or multi-dimensional poverty to assess this. However, low income and fragile states typically have higher rates of poverty and poverty severity than stable middle income countries which raises the question, even if middle income countries are home to the world’s poor, where do the world’s poorest live? This paper seeks to answer this question taking a multi-dimensional approach to poverty. Three approaches to identifying the ‘Bottom Billion’: by countries (eg low and middle income); by sub-national regions (as the poor may live in low-income regions of otherwise prosperous countries) and by poverty profiles of individuals from every survey household across 104 countries. Although the different approaches produce different findings there are notable commonalities across the approaches that are of relevance to the discussions of post-2015 development goals.