Background: Public libraries can contribute to reducing economic, social, and health inequities through their programming and practices. However, the extent to which libraries regularly provide programming that improve the social determinants of health (SDH) in underserved communities is unclear. Objective: This study explored the relationship between census tract demographic characteristics and library programming implicated in the SDH for underserved groups at risk for health disparities. Method: A stratified random sample of libraries (n = 235) who completed the 2017 Public Libraries Survey were recruited. Librarians completed surveys about their libraries’ economic, social, and health-related programming. Libraries’ census tract demographic characteristics were taken from the 2013–2017 American Community Survey. Linear regressions were estimated to determine the relationship between relevant census tract demographic characteristics and programming offered at libraries in the census tracts. Results: Higher proportions of racial and ethnic minorities were associated with more frequent economic and social programs, but results were mixed for health-related programs. Lower proportions of populations with no more than a high school diploma or GED were related to more frequent economic, social, and health-related programs. Conclusions: The inequitable distribution of SDH-related library programming highlights gaps in libraries’ responsiveness to community needs. Libraries’ programming likely perpetuate systemic inequities.