Tackling health inequalities is a policy priority. Research on cancer and particularly oral cancer aetiology has somewhat overlooked this area, in favour of pursuing genetic and 'lifestyle' risk factors. The over-arching aim of this thesis was to investigate the epidemiology of oral cancer in relation to individual socioeconomic status (SES), area-based socioeconomic circumstances, and socioeconomic inequalities. Descriptive epidemiology studies undertaken demonstrated that the burden of oral cancer was increasing across the UK, especially in Scotland, and a socioeconomic gap was widening with those from more deprived communities having significantly greater and increasing incidence of the disease. A systematic review and meta-analysis of the world literature showed that low compared to high SES was associated with significantly elevated risk of oral cancer independent of behavioural factors. A local case-control study provided unclear findings when individual- and area-based socioeconomic factors were explored together; however, a framework for future analyses was developed. In totality, this thesis suggests that public health policy to address the overall rising incidence and widening inequalities of oral cancer needs to acknowledge the complexity of the risk factors; in addition, the findings provide evidence to steer policy, which focus on lifestyles factors towards an integrated approach incorporating measures designed to tackle the root causes of disadvantage.