Sleep disturbances are commonly experienced by people living with Borderline Personality Disorder (BPD). Preliminary evidence suggests that young people with BPD experience poorer sleep quality in comparison to controls. However, inconsistent findings amongst adults have rendered it difficult to confidently characterise whether there is a particular sleep phenotype associated with BPD. The aim of this study was to investigate the subjective experience of sleep quality and factors that may influence this. The study also explored the prevalence and content of remembered dreams/nightmares in people with BPD and whether participants believed that these were linked with previous trauma. An anonymous cross-sectional self-report survey was disseminated across Australia and globally to recruit adults with BPD. 168 people completed the survey. As hypothesised, the majority of people with BPD self-reported problems with their sleep quality, with many experiencing nightmares with possible links to previous trauma. Participants also reported a high prevalence of medication and substance use to improve sleep quality. The results suggested the existence of important interconnections between sleep quality and symptomatic expression and severity of BPD, highlighting the need for further studies to better understand the treatment and support implications of this association.