Hassan Mustafa Osama Nasr (Arabic: حسن مصطفى أسامة نصر) (born 18 March 1963), also known as Abu Omar, is an Egyptian cleric. He was living in Milan, Italy when he was allegedly kidnapped by the CIA and tortured in Egypt. The "Imam Rapito affair" prompted a series of investigations in Italy.
He is a member of al-Gama'a al-Islamiyya, an Islamic organisation dedicated to the overthrow of the Egyptian government. The group has been linked to the murder of Anwar Sadat in 1981 and a terrorist campaign in the 1990s that culminated in the November 1997 Luxor massacre. As a result it is considered a terrorist organization by the United States and European Union. After the Egyptians declared the group illegal, Nasr sought asylum in Italy.
While in Albania in the mid-1990s, Nasr is reported to have served as an informant for the Albanian national intelligence service, SHiK.