The Pipeline and Hazardous Materials Safety Administration (PHMSA) is a United States Department of Transportation agency created in 2004, responsible for developing and enforcing regulations for the safe, reliable, and environmentally sound transportation of energy and other hazardous materials. It is in charge of overseeing about 3.4 million miles of pipelines - accounting for 65% of the energy consumed in the U.S. - and regulating the nearly 1 million daily shipments of hazardous materials by land, sea, and air. This includes pipelines carrying carbon dioxide Carbon capture and utilization). PHMSA's safety programs are housed in the Office of Pipeline Safety (OPS) and the Office of Hazardous Materials Safety (OHMS). PHMSA is headquartered in Washington, D.C.

The United States Department of Transportation is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States and is a member of the president's Cabinet.