Although much has been said about livestock’s role in achieving food security, in reality, the subject has been only partially addressed and no current document fully covers the topic. Recognizing that food security is central to international development – and to the mandate of FAO - this report tells the story of livestock and food security from three perspectives. It begins by presenting a global overview, examining the role that livestock play in human nutrition, the world food supply and access to food particularly for poor families. Next it moves from the global level to a human perspective, examining the way in which livestock contributes to the food security of three different human populations –livestock-dependent societies, small-scale mixed farmers and urban dwellers. The final part of the report looks to the future. It discusses the expected demand for livestock source food and the way that increased demand can be met with ever more limited resources. It reviews the drivers that led to the livestock revolution, how these have changed and what the implications will be for livestock contributing to resilient food systems of the future.