Mental health services are underused relative to mental illness rates. We hypothesized a positive correlation between use of mental health services and community-level health care social capital. Community Tracking Study data from 43 cities (N = 43,278), merged with the National Profile of Local Health Departments and other sources, show that use of mental health services was greater when public health districts collaborated with managed care organizations and other community groups, independent of individual predictors and health care system variables. Use was also positively associated with community levels of public insurance coverage and with direct public health provision of behavioral health care services. Research is needed to understand the mechanisms by which social capital may improve access to mental health services.