In 2018, almost 300 million people connected to mobile internet for the first time, bringing the total connected population to more than 3.5 billion people globally. For many of these individuals, mobile is the only method of accessing the internet, so growth in mobile internet adoption also drives digital inclusion, especially in low- and middle-income countries (LMICs). Mobile internet connectivity is not, however, equitable; just over 40% of the LMIC population are connected, compared to almost 75% of the population in high-income countries. More than half the world’s population are therefore still unable to realise the social and economic benefits that mobile internet can enable. This report accompanies the fourth annual update of the GSMA Mobile Connectivity Index – a tool that measures the performance of 165 countries (representing 99% of the global population) against the key enablers of mobile internet adoption: infrastructure; affordability; consumer readiness; and content and services. Key findings from the Index are analysed in this report alongside other relevant data sources, including the GSMA Intelligence Consumer Survey 2018.