Mehmet Ali Ağca (Turkish pronunciation: [mehˈmet aˈli ˈaːdʒa]; born 9 January 1958) is a Turkish assassin who murdered left-wing journalist Abdi İpekçi on 1 February 1979, and later shot and wounded Pope John Paul II on 13 May 1981, after escaping from a Turkish prison. After serving 19 years of imprisonment in Italy where he was visited by the Pope, he was deported to Turkey, where he served a ten-year sentence. According to his own words, he converted to the Roman Catholic Church on 13 May 2007 (the 26th anniversary of his deed).

Ağca was released from prison on 18 January 2010. He described himself as a mercenary with no political orientation, although he is known to have been a member of the fascist, Islamic Turkish ultra-nationalist Grey Wolves organization and the state-sponsored Counter-Guerrilla.On 27 December 2014, 33 years after his crime, Ağca publicly arrived at the Vatican to lay white roses on the recently canonized John Paul II's tomb and said he wanted to meet Pope Francis, a request that was denied.