The objective of the study was to describe self-report and objectively measured sleep characteristics of adult treatment-seeking cannabis users. Study participants (n = 87) were adults who were screened for a 12-week outpatient cannabis treatment research program in Baltimore, MD. Participants completed objective and self-report measures of sleep quality. Data were analyzed for the sample overall and after stratifying by sex (54 men, 33 women). Participants were primarily urban, socioeconomically disadvantaged African Americans. Participants were frequent, heavy cannabis users; among a subset of participants assessed, 76.7% used cannabis on the day/night of the assessment. Participants had low rates of other substance abuse and of psychiatric comorbidities. Polysomnography indicated 19.5% of participants received the recommended 7 to 9 hr of sleep, with women averaging more sleep than men. One third (31.0%) had sleep latencies >30 min, one half spent >30 min awake after sleep onset, and more than one half of the sample (55.2%) had sleep efficiency scores of <85%. Most participants met criteria for subthreshold (36.8%) or clinical insomnia (25.3%) on the Insomnia Severity Index, 77.0% had scores of >5 on the Pittsburgh Sleep Quality Index. Most had average scores on the Dysfunctional Beliefs and Attitudes About Sleep (DBAS) questionnaire (M = 51.1, SD = 18.8) that were higher than average among clinical insomnia patients. Women had higher DBAS scores than men. Most participants exhibited characteristics of disordered sleep, and sex differences were observed on polysomnography and self-report measures. Findings extend prior research concerning the association between cannabis use and disordered sleep. Data presented in this article come from Clinical Trial NCT01685073.