Introduction: Cannabis use among adults in the United States is growing, and while case reports and animal studies suggest a relationship between its use and delirium, no clinical studies have assessed the potential association. Therefore, this study aims to determine whether there is an association between a history of cannabis use disorder and delirium. Methods: The TriNetX Analytics Network, a research platform containing de-identified electronic health records from over 116 million patients and 63 healthcare organizations across the United States was utilized. History of cannabis use disorder was defined as at least 1 diagnosis of Cannabis related disorders (ICD-10-CM F12) within 1 year prior to hospitalization or surgery. Propensity score matching based on demographic characteristics (age, sex, race, and ethnicity) and comorbidities (diabetes, cardiovascular disease, neurological disease, dementia, depression, substance use, physical disabilities) was performed. The primary outcome is a diagnosis of delirium due to a known physiological condition (ICD-10-CM F05) within either 2 weeks (in-patient hospitalization analyses) or 1 week (post-operative analyses) of the respective hospital event. Results: Following a propensity score match, 178,275 individuals were included in the 18-64 years in-patient cohort, 16,307 individuals in the 65+ in-patient cohort, 85,314 individuals in the 18-64 post-operative cohort, and 11,136 individuals in the 65+ post-operative cohort. In the in-patient hospitalization analysis, there was a significant association between cannabis use and delirium in the 18-64 cohort (HR: 1.43, 95% CI: 1.11 – 1.85) but not in the 65+ cohort (HR: 1.19, 95% CI: 0.66 – 2.12). In the postoperative setting, there was a significantly increased risk of delirium in the cannabis cohort in both the 18-64 (HR: 3.37, 95% CI: 2.59 – 4.39) group and 65+ years old group (HR: 2.37, 95% CI: 1.51 – 3.72). Conclusions and Relevance: The findings of this investigation suggest that documented cannabis-use disorder within one year of hospitalization or surgery is associated with a significantly increased risk of delirium. Delirium is associated with considerable patient morbidity, which can be mitigated through early diagnosis. Documented cannabis use may, therefore, warrant additional delirium screening measures and clinical discretion.