Sahibzada Mīrzā Mu'hammad Jalāl ud-Dīn Mridha Sahib, better known as Jalaluddin Mirza (1898–1975), was a Bengali Indian aristocrat in the erstwhile British Empire who served as the fifth and last hereditary Zamindar of Natore from the House of Singra and Natore before it was abolished in 1951.
One of the few Muslim zamindari in Natore, during the Partition of India in 1947 the newly formed Islamic Government of Pakistan favored Muslim families and especially when Bengal was split the old Hindu Rajas (Kings) of East Bengal left resulting in most of the neighboring estates coming under him and his full brothers.
He died in 1975 and his oldest child Gulbadan Begum of Natore (1923-2005) succeeded him as the head of the Singranatore family.
In 1950 during the abolition, the Singra Natore Zamindari was at its fullest extent, annexing villages formerly governed by High caste Hindu families.
Most of his children were married off to notable land holding and feudal noble families of aristocratic lines.