Sayyid Najabat Ali Khan Bahadur, born Mir Phulwari (Bengali: নজাবত আলী খান; 1749 – 10 March 1770), better known as Saif ud-Daulah, succeeded his younger brother Nawab Nazim Najimuddin Ali Khan, after his death in 1766, as the Nawab Nazim of Bengal and Bihar.

He reigned under the regency of his mother and died of smallpox on 10 March 1770, during the Great Bengal famine of 1770.

After the death of Najimuddin Ali Khan, his younger brother Najabat Ali Khan, better known as Saif ud-Daulah, succeeded him and was placed on the Masnad (throne) at the age of 17.

Saif ud-Daulah was formally installed on the Khahar Balish, at Murshidabad Fort on 22 May 1766, which was confirmed by Mughal Emperor Shah Alam II on 27 June 1766.

[citation needed] In 1770, during Bengal famine of 1770, a great epidemic of small pox raged in Murshidabad and killing 63,000 of its inhabitants, one of them being Nawab Nazim Saif ud-Daulah, himself.