Confirmation bias is a universal characteristic of human cognition, with consequences for information processing and reasoning in everyday situations as well as in professional work such as forensic interviewing. Cognitive measures such as general intelligence are also related to personality traits, but there is a lack of research on personality and confirmation bias specifically. This study focuses, firstly, on the relationship between Big Five personality traits and confirmation bias as measured by the Wason selection task, and secondly, how these dispositions are related to observed performance in real forensic interviews of child victims. In a sample of police interviewers, Openness (i.e., the facets Ideas and Fantasy) and Neuroticism (i.e., the facets Anxiety and Vulnerability) were independently associated with confirmation bias (N = 72). Scores on the selection task, the Openness facet values, and the Extraversion facets Assertiveness and Activity were consistently related to interview performance (N = 46). Implications of these findings are discussed for the empirical and conceptual relations of cognitive ability to personality and for the selection and training of police interviewers and their professional development.