| Al-Qasim al-Ma'mun القاسم المأمون | |
| Succession: | 7th Caliph of Córdoba (first period) |
| Issue: | Ali ibn Hammud |
| Issue-Type: | Brother |
| Reign: | 1018 – 1021 |
| Predecessor: | Ali ibn Hammud |
| Successor: | Yahya ibn Ali |
| Succession1: | (second period) |
| Reign1: | 1023 |
| Predecessor1: | Yahia ibn Ali |
| Successor1: | Abd ar-Rahman V |
| Full Name: | Al-Qasim al-Ma'mun ibn Hammud (Arabic: القاسم المأمون بن حمود) |
| Dynasty: | Hammudid |
| Religion: | Islam |
Al-Qasim al-Ma'mun ibn Hammud (Arabic: القاسم المأمون بن حمّود, died 1036) was an Arab Caliph of Córdoba in Muslim Spain for two periods, 1018 to 1021, and again for a short time in 1023 until he was driven from the city.[1] He hailed from the Banu Khazraj tribe. He was the brother of the deposed Ali ibn Hammud al-Nasir.[2] His reign was described in Ibn al-Khatib's A'mal al-a'lam.
This was during a short period when the caliphate was held by the Hammudid dynasty.