Background Half of Americans experience mental illness during their lifetime. Significant opportunity exists for community pharmacists to deliver services to these patients; however, personal and practice-related barriers may prevent full engagement. Objective To assess the demographics, practice characteristics, service provision, stigma, attitudes and beliefs of a national sample of community pharmacists towards individuals with mental illness. Setting National random sample of 3008 community pharmacists in the USA. Method 101-item cross-sectional mailed survey questionnaire on: (1) demographics, (2) knowledge and practice characteristics, (3) provision of clinical pharmacy services, and (4) comparative opinions. Main outcome measure Scaled measures of service provision (comfort, confidence, willingness and interest) and comparative opinions (stigma, attitudes and beliefs) of mental illness, four linear regression models to predict service provision. Results A total of 239 responses were received (response rate 7.95%). Across pharmacy services, ratings for willingness/interest were higher than those for comfort/confidence. Pharmacists who reported providing medication therapy management (MTM) services for patients reported higher comfort (18.36 vs. 17.46, p < 0.05), confidence (17.73 vs. 16.01, p < 0.05), willingness (20.0 vs. 18.62, p < 0.05) and interest (19.13 vs. 17.66, p < 0.05). Pharmacists with personal experience with mental illness also resulted in higher scores across all four domains of service provision, lower levels of stigma (18.28 vs. 20.76, p < 0.05) and more positive attitudes (52.24 vs. 50.53, p < 0.01). Regression analyses demonstrated increased frequency of MTM service delivery and more positive attitudes as significantly predictive across all four models for comfort, confidence, willingness and interest. Increased delivery of pharmacy services was significantly associated with both willingness and interest to provide mental illness-specific services. Conclusion Despite willingness/interest to provide services to patients with mental illness, decreased levels of comfort/confidence remain service-related barriers for community pharmacists.