Poor quality sleep is common for people who have a diagnosis of personality disorder (PD). Core cognitive and behavioral features of PD may cause and perpetuate poor sleep, but to date, no review has collated the evidence on the efficacy of interventions to improve sleep quality for people with PD. Structured searches for interventional studies among adults with PD and reporting validated measures of sleep quality were conducted up to November 2022 in multiple databases. Single-case reports were excluded. Study quality was assessed with standardized risk of bias tools. Unreported data was sought systematically from authors. This review was pre-registered with an international prospective register of systematic reviews (PROSPERO) (CRD42021282105). Of the 3503 identified studies, nine met inclusion criteria, representing a range of psychological, pharmaceutical, and other interventions and outcome measures. Meta-analytic methods were not feasible because of the serious risk of bias in all studies, and results were therefore synthesized narratively. There is limited and low-quality evidence of the effects of a variety of interventions to improve the sleep quality of people living with PD. Further research might consider specifically including people diagnosed with PD in trials of sleep interventions and using sleep outcome measures in trials of established PD treatments.