| Ala ud din Masud | |
| Reign: | 15 May 1242 – 10 June 1246 |
| Full Name: | Alauddin Masood Shah bin Rukhuddin Firuz Shah bin Shamsuddin Iltumish |
| Predecessor: | Muiz ud din Bahram |
| Successor: | Nasiruddin Mahmud |
| Spouse: | Unknown |
| Issue: | Unknown |
| Royal House: | Slave dynasty |
| Dynasty: | Mamulk |
| Father: | Rukn ud-Din Firuz |
| Birth Date: | 1225 |
| Birth Place: | Delhi |
| Death Date: | 10 June 1246 (aged 21) |
| Death Place: | Delhi |
| Religion: | Sunni Islam |
| Succession: | 7th Sultan of Delhi |
| Sultan | |
Ala ud-Din Masud Shah (Persian: {{nq|علاء الدین مسعود شاه; died 10 June 1246,) was the seventh sultan of the Delhi Sultanate.
He was the son of Rukn ud-Din Firuz (1236), son of Sultan Illtutmish and Shah Turkan and the nephew of Sultan Raziyyat (1236–40). After his predecessor and uncle Muiz ud-Din Bahram was murdered by the army in 1242 after years of disorder, the chiefs chose for him to become the next ruler of Delhi. However, he was more of a puppet for the chiefs and did not actually have much power or influence in the government. Instead, he became infamous for his fondness for entertainment and wine. Like his predecessor, he was considered "incompetent and worthless." By 1246, the chiefs became upset with his increasing hunger for more power in the government, and executed him, replacing him with Nasiruddin Mahmud Shah.
Gold, Silver and Billon coins are known for Ala ud-Din Masud Shah. Gold and silver coins were issued from Lakhnau and Delhi. Billon coins were struck from Budaun and Delhi.