Global indices are a way to assess and compare national progress against international goals, such as the Sustainable Development Goals, by distilling complex information into a single number. Such composite indices can capture and synthesize an array of data in a way that can be readily understood and that is especially informative for multidimensional concepts. The new global Women, Peace, and Security (WPS) Index introduced in this report bridges insights from gender and development indices with those from peace and security indices. The index incorporates three basic dimensions of wellbeing—inclusion (economic, social, political); justice (formal laws and informal discrimination); and security (at the family, community, and societal levels)—and captures and quantifies them through 11 indicators. It ranks 153 countries—covering more than 98 percent of the world’s population—along these three dimensions in a way that focuses attention on key achievements and major shortcomings. It reflects a shared vision that countries are more peaceful and prosperous when women are accorded full and equal rights and opportunity.