The Global Gender Gap Index (GGGI) is regarded as a significant indicator of gender disparity worldwide. It’s useful tracking of the extent of access to resources and opportunities, and differences between men and women have been discussed across sectors and levels of decision making. The chapter encapsulates origin and history of GGGI, methodology for data collection and computation. The analysis covers critical aspects involving the four sub-indexes (dimensions): economic participation and opportunity, educational attainment, health and survival, and political empowerment. These sub-indexes and their indicators for the development of GGGI have been elucidated. Based on the Global Gender Gap Report (WEF 2018), a brief overview of country comparisons and rankings has been provided. The application of the index for policy formulation and application in consulting, forms part of the chapter. The strengths and weaknesses of the GGGI along with suggestions have been provided for potential future use.