Prince Mansour's first government post was the supervision of the royal palaces in Riyadh which he was appointed in 1938. In 1940 he was made minister of war.{{cite book|author=C. H. H. Owen|title=The Naval Miscellany|volume=VI|page=433|chapter-url=https://books.google.com/books?id=oxEIEAAAQBAJ&pg=PA433|year=2020|publisher=
Routledge|isbn=978-1-00-034082-2|location=London; New York Then Prince Mansour was appointed minister of defense and aviation by King Abdulaziz on 10 November 1943 when the office was established which had been titled as the ministry of war since 1940.{{cite web|title=Royal Saudi Land Forces History In December 1944 Prince Mansour visited Khartoum where Saudi army personnel were trained in driving and maintenance. He and King's another son,
Muhammad, accompanied their father in his meetings with the US President
Franklin D. Roosevelt on 14 February 1945{{cite book|author=William A. Eddy|author-link=William A. Eddy|title=FDR meets Ibn Saud|year=2005 Prince Mansour asked the British to reorganize the Saudi armed forces in November 1944.{{cite thesis|title=Anglo-American relations in Saudi Arabia, 1941-1945: a study of a trying relationship|location=
London School of Economics|author=Matthew Hinds|year=2012|degree=PhD|page=167 Prince Mansour also headed the
Saudi Arabian Airlines when he was serving as defense minister. His term as defense minister lasted until his death in 1951, and he was replaced by his full brother Prince Mishaal who had been his deputy at the ministry. ==Personal life==