Muhammad Hosni El Sayed Mubarak (Arabic: محمد حسني السيد مبارك‎, Egyptian Arabic pronunciation: [mæˈħæmmæd ˈħosni (ʔe)sˈsæjjed moˈbɑːɾɑk], Muḥammad Ḥusnī Sayyid Mubārak ; born 4 May 1928) is a former Egyptian military and political leader who served as the fourth President of Egypt from 1981 to 2011.

Before he entered politics, Mubarak was a career officer in the Egyptian Air Force. He served as its commander from 1972 to 1975 and rose to the rank of air chief marshal. Some time in the 1950s, he returned to the Air Force Academy as an instructor, remaining there until early 1959. He was appointed Vice President of Egypt by President Anwar Sadat in 1975 and assumed the presidency on 14 October 1981, eight days after Sadat's assassination. Mubarak's presidency lasted almost thirty years, making him Egypt's longest-serving ruler since Muhammad Ali Pasha, who ruled the country from 1805 to 1848. Mubarak stepped down after 18 days of demonstrations during the 2011 Egyptian revolution. On 11 February 2011, Vice President Omar Suleiman announced that Mubarak had resigned as president and transferred authority to the Supreme Council of the Armed Forces.