To determine the prevalence of sleep disturbance during the coronavirus disease 2019 (COVID-19) pandemic among US adults who are more vulnerable to complications because of age and co-morbid conditions, and to identify associated sociodemographic and psychosocial factors. Cross-sectional survey linked to 3 active clinical trials and 2 cohort studies, conducted between 11/30/2020 and 3/3/2021. Five academic internal medicine practices and 2 federally qualified health centers. A total of 715 adults ages 23 to 91 years living with one or more chronic conditions. A fifth (20%) of participants reported poor sleep. Black adults were twice as likely to report poor sleep compared to Whites. Self-reported poor physical function (51%), stress (42%), depression (28%), and anxiety (36%) were also common and all significantly associated with poor sleep. Age ≥70 years and having been vaccinated for COVID-19 were protective against poor sleep. Sex, education, income, alcohol use, and employment status were not significantly associated with sleep quality. In this diverse sample of adults with chronic conditions, by race, ethnicity, and socioeconomic status, disparities in sleep health amid the ongoing pandemic were apparent. Worse physical function and mental health were associated with poor sleep and should be considered targets for health system interventions to prevent the many subsequent consequences of disturbed sleep on health outcomes. Measurements: self-reported sleep quality, physical function, stress, depression, and anxiety. Abbreviations: AUDIT-C = the 3-question alcohol use disorders identification test, C3 = the COVID-19 & chronic conditions study, CDC = the centers for disease control and prevention, CHAI = the consumer health activation index, COPD = chronic obstructive pulmonary disease, COVID-19 = coronavirus disease 2019, FDA = US Food and Drug Administration, MESA = multi-ethnic study of atherosclerosis study, PROMIS = Patient-Reported Outcomes Information System, PROMIS-SD = Patient-Reported Outcomes Information System Sleep Disturbance Battery, PSQI = Pittsburgh sleep quality index, PSS-10 = Cohen's 10-item perceived stress scale, VOC = variant of concern.