This thesis examines the role of evidential relevance in the context of criminal trials. Despite being a central concept in the law of evidence, there is little academic literature examining the precise role that relevance plays in admitting evidence in criminal trials. This thesis will examine the nature of ‘evidential relevance’ and explore how relevance works in the context of three specific types of evidence, these being bad character evidence, sexual history evidence and hearsay evidence. This thesis will supplement a doctrinal and theoretical examination of evidential relevance with a practical exploration of its use. To gain an insight into the practical use of relevance by legal professionals, the research will draw upon in-depth qualitative interviews with barristers and judges.