Ibn Ammar (Arabic: ابن عمار; 1031–1086) was a Muwallad poet from Silves.
Ibn Ammar, descended from a Portuguese Muslim family, became Grand Vizier of the taifa of Seville. Though he was poor and unknown, his skill in poetry brought him the friendship of the young Abbad III al-Mu'tamid, who named him prime minister some time after the death of his father Abbad II al-Mu'tadid. Ibn Ammar was reputed to be unbeatable at chess; according to Abdelwahid al-Marrakushi, his victory in a game convinced Alfonso VI of Castile to turn away from Seville.
He engineered the annexation of the taifa of Murcia to the kingdom of Seville, and convinced Al-Mu'tamid to name him as its governor. He proclaimed himself its king and cut off relations with Al-Mu'tamid. He soon fell from power, was captured in an ambush, and was imprisoned in Seville. Al-Mu'tamid was initially inclined to forgiveness, but was later incensed by something he read in an intercepted letter sent by Ibn Ammar from his prison cell. The king then killed the poet with his own hands.