Mustapha Ben Ismaïl (Arabic: مصطفى بن اسماعيل; born around 1850 in Bizerte and died in 1887 in Istanbul)[1] was a Tunisian politician.

Some hostile sources make him the son of a Jewish convert and an unknown Tunisian man, with his mother remarrying to a Muslim and settling in Tunis.

Subsequently, he is meant to have begged on the streets of the capital, worked in a Maltese tavern and then for a barber, before being hired by an offer of the guard of the Bey of Tunis, who brought him into the palace.

During his vizierate, Ben Ismaïl stirred up the anger of the Bey against Hayreddin's reforms and policy of court austerity.

The establishment of the French protectorate of Tunisia and the death of Sadok Bey in 1882 ruined his career, but he managed to retain a small part of his fortune and fled to Istanbul, where he became obscure.