This collection features five peer-reviewed literature reviews on sensor technologies in livestock monitoring. The first chapter considers the development of on-animal sensors as a means of monitoring an array of livestock species, as well as the challenges which arise with their deployment in commercial livestock management operations. The second chapter reviews the utilisation of wearable technologies to monitor the welfare of poultry, including accelerometers. The chapter also considers the effects of these sensors on bird welfare and behaviour. The third chapter provides a detailed overview of recent advances in techniques for monitoring dairy cow health and welfare. The chapter reviews the development of diagnostic tools and sensor technologies which enable automated, continuous monitoring of livestock. The fourth chapter reviews the potential of precision livestock farming (PLF) technology to monitor dairy cattle welfare in line with the Five Domains framework. The chapter explores how PLF can positively impact each of the five domains: nutrition, environment, health, behaviour and mental state. The final chapter reviews recent advances in technologies for monitoring key indicators of pig welfare by considering good feeding, good housing, good health and appropriate behaviour.