William Thaddeus Coleman Jr (July 7, 1920 -) was the USA's fourth Secretary of Transportation and the second African American to serve in the Cabinet. Serving from March 7, 1975 to January 20, 1977, Coleman was a distinguished lawyer who, with Thurgood Marshall, had played a major role in significant civil rights cases.

During Coleman's tenure at the Department, NHTSA's automobile test facility at East Liberty, Ohio commenced operations, and the department established the Materials Transportation Bureau to address pipeline safety and the safe shipment of hazardous materials. On leaving the Department, Coleman returned to Philadelphia, but subsequently became a partner in the Washington office of the Los Angeles-based law firm O’Melveny and Myers. In 1996, in the wake of the July 17 crash of TWA Flight 800, he served on the President's Commission on Airline and Airport Security. That same year, Coleman received the Presidential Medal of Freedom, the highest honor given to civilians by the United States.