A quarter of a century ago, Heather Joshi edited a landmark volume (sponsored by the British Society for Population Studies and the Centre for Economic Policy Research) entitled The Changing Population of Britain. In 2014-15, to mark the 25th anniversary of this book, the BSPS teamed up with the British Academy to hold a series of events on population developments in the UK and the policy issues that they raise, and has built on these presentations to produce a new edited collection on the changing population of the UK. This book shows that the UK's population is increasing faster than at any point in the last 100 years, it is getting progressively older and it is becoming more diverse culturally and ethnically. More school leavers are going on to university. Cohabitation has been replacing marriage, more children live in one-parent families and young adults are finding it harder to get on the property ladder. Many women are delaying having children until their 40s. Cities have seen a resurgence in population but there is still pressure on the countryside, while the north-south divide is getting ever wider, as too are local socio-economic disparities. The contributors to this book document these changes, examine their causes and discuss future prospects and their policy implications.