Al-Muzaffar Sayf ad-Din Hajji ibn Muhammad ibn Qalawun, better known as al-Muzaffar Hajji, was the Bahri Mamluk sultan of Egypt. He was also the sixth son of an-Nasir Muhammad to hold office, ruling from September 1346 and December 1347. He was known for his love of sports and pigeon racing, acts which led to frustration among the senior Mamluk emirs who believed he neglected the duties of office and spent extravagant sums on gambling. His reign ended when he was killed in a confrontation with Mamluk conspirators outside of Cairo.

The Bahri Mamluks, sometimes referred to as the Bahri dynasty, were the rulers of the Mamluk Sultanate of Egypt from 1250 to 1382, following the Ayyubid dynasty. The members of the Mamluk ruling class were purchased as slaves (mamluks) and manumitted, with the most powerful among them taking the role of sultan in Cairo. While several Bahri Mamluk sultans tried to establish hereditary dynasties through their sons, these attempts were ultimately unsuccessful, with the role of sultan often passing on to another powerful Mamluk.