Non-alcoholic fatty liver disease (NAFLD) is intricately linked to metabolic disease (including obesity, glucose intolerance, and insulin resistance) and encompasses a spectrum of disorders including steatosis, non-alcoholic steatohepatitis (NASH) and fibrosis. A variety of animal models that mirror both the histopathology and the pathophysiology of each stage of NAFLD/NASH are available, including rodents, but also certain large animals such as pigs and non-human primates.