By 2050, the global population living in cities is projected to reach 5 billion, growing from 3.5 billion in 2015. Massive investment in infrastructure will be needed to accommodate this growth, and to adapt infrastructure to climate change and benefit from the digital transition. This report explores three ways to meet this challenge. Firstly, it outlines how new forms of urban planning can help to mobilise private finance for inclusive, resilient and sustainable urban investment. Secondly, it explores how leveraging private investment can help to strengthen cities capacity to support needed investment in a tighter fiscal environment. Finally, it considers the potential opportunities and challenges for mobilising sustainable finance – green, social and sustainable bonds and loans, sustainability-linked bonds and catastrophe bonds – for infrastructure investment by City Governments. The report also includes 17 short case studies from 12 countries that demonstrate innovative practices for creating the Cities of Tomorrow.