Lawrence Francis O'Brien Jr. was an American politician and basketball commissioner. He was one of the United States Democratic Party's leading electoral strategists for more than two decades. He was Postmaster General in the cabinet of President Lyndon Johnson and chair of the Democratic National Committee. O'Brien was also commissioner of the National Basketball Association from 1975 to 1984, and the NBA Championship Trophy is named after him.

The United States postmaster general (PMG) is the chief executive officer of the United States Postal Service (USPS). The PMG is responsible for managing and directing the day-to-day operations of the agency.