William McCombe Callaghan (August 8, 1897 – July 8, 1991) was a United States Navy officer who served as the first captain of the battleship and the inaugural commander of the Military Sea Transportation Service. Through the course of almost 40 years, he served his country in three wars. His naval career began on a destroyer in the final months of World War I. Following command of the destroyer and logistical work prior to World War II, he took command of "Missouri" in 1944.