The current study investigated the relation between sleep disturbance (assessed by self-report and actigraphy) and paranoia in a transdiagnostic sample with psychosis. It also assessed the impact that negative affect (depression-anxiety) and social cognitive bias (tendency to blame others) have on this association. Twenty-seven participants with a psychotic disorder, who were recruited from a larger pilot study, completed clinical interviews and self-report questionnaires related to paranoia, sleep disturbance, sleep-related impairment, negative affect, and social cognitive bias. After completing these assessments, participants wore an actigraph watch for seven consecutive days to assess their sleep-wake patterns. Results indicated that paranoia was associated with sleep-related impairment and social cognitive bias, but it was not related to depression-anxiety or any measures of sleep disturbance. These results suggest that paranoia may be impacted by some aspects of sleep and social cognitive bias, which could inform future interventions.