Drinking water services in the U.S. are critical for public health and economic development but face technical, political, and administrative challenges. Understanding the root cause of these challenges and how to overcome them is hindered by the lack of integrative, comprehensive data about drinking water systems and the communities they serve. The Municipal Drinking Water Database (MDWD) fills a critical gap by combining financial, institutional, political, and system conditions of U.S. municipalities and their community water systems (CWS) to enable researchers and practitioners interested in viewing or tracking drinking water spending, the financial condition of city governments, or myriad demographic, political, institutional, and physical characteristics of U.S. cities and their drinking water systems to access the data quickly and easily. The MDWD focuses on municipally owned and operated CWS, which are ubiquitous and play a critical role in ensuring safe, affordable drinking water services for most Americans. They also offer important opportunities for understanding municipal government behavior and decision making. The MDWD is a unique dataset of municipal CWSs in the U.S. that includes information about their residents, their city governments, and their drinking water systems.