| Mudzaffar Shah I | |
| Sultan of Kedah | |
| Reign: | 1136– 27 July 1179 |
| Successor: | Mu'adzam Shah |
| Issue: | Sultan Mu'adzam Shah Tunku Muhammad Shah Tunku Sulaiman Shah |
| House: | Mahawangsa |
| Father: | Dharmawira of Srivijaya |
| Death Date: | 27 July 1179 |
| Religion: | Sunni Islam |
Paduka Sri Sultan Mudzaffar Shah I (Jawi: Malay: ڤدوك سري سلطان مظفر شاه ١; died 27 July 1179), styled Phra Ong Mahawangsa was a legendary king and was said to be the first Sultan of Kedah, according to the Hikayat Merong Mahawangsa. He was the last Hindu King of Kedah, styled Sri Paduka Maharaja Durbar Raja before his accession. After his conversion to Islam,[1] he later became the founder of the Kedah Sultanate.