Fatimah bint Hizam al-Kilabiyya (Arabic: فاطمة بنت حزام الكلابية) commonly known as Umm ul-Baneen (أم البنين) was the wife of Imam Ali ibn Abu Talib (as) who he married a few years after the martyrdom of his first wife, Fatima bint Muhammad.
Imam Ali (as) asked his brother Aqeel, an expert at Arab genealogy, to select a lady from any tribe that is known for its exceptional valor so that she would gave birth to valorous sons. Aqeel advised him to marry Umm ul-Baneen whose tribe was famous in Arabia for their exploits of chivalry and bravery. She gave birth to four sons, Abbas, Abdullah, Uthman and Ja'far. All four brothers were martyred at the Battle of Karbala.