William Ralph Basham Jr. is an American law enforcement official who served as commissioner of U.S. Customs and Border Protection, director of the United States Secret Service, director of the Federal Law Enforcement Training Centers, and chief of staff of the Transportation Security Administration.

United States Customs and Border Protection (CBP) is the largest federal law enforcement agency of the United States Department of Homeland Security. It is the country's primary border control organization, charged with regulating and facilitating international trade, collecting import duties, as well as enforcing U.S. regulations, including trade, customs and immigration. CBP is one of the largest law enforcement agencies in the United States. It has a workforce of more than 45,600 federal agents and officers. It is headquartered in Washington, D.C.