BackgroundThis study investigated the association between fair and supportive leadership and symptoms of burnout and insomnia in police employees. Burnout and insomnia can have negative consequences for health, performance, and safety among employees in the police profession, and risk and protective factors should be thoroughly investigated. MethodsData were collected in a police district in Norway through questionnaires administered in October 2018 and May 2019. The sample consisted of 206 police employees (52% males), with an average age of 42 years and 16 years of experience in the police occupation. ResultsThe results showed that a high degree of fair and supportive leadership was associated with lower levels of burnout and insomnia six months later. Fair and supportive leadership explained a greater amount of variance in burnout compared to insomnia. This finding indicates that fair and supportive leadership is a more important buffer factor against burnout than it is against insomnia. Stress was positively associated with burnout and insomnia, whereas quantitative job demands had no significant association with the concepts. ConclusionFair and supportive leadership can help protect employees from adverse consequences of stress and contribute to improved occupational health, whereas a low degree of support and fair treatment from leaders can both represent a stressor by itself and contribute to poorer coping of stressful events at work. The important role of leadership should be incorporated in measures aimed at preventing and reducing burnout and sleep problems.