Maulana Mir Abdullah Bihari (1819–1882) was an eminent Indian Muslim scholar, theologian, author and teacher from Bihar. He was among the distinguished Muslim scholars of nineteenth-century Bihar and is remembered with great respect for his contributions to Islamic scholarship, Sufism, religious education and moral reform. His life was devoted to the dissemination of Islamic knowledge, teaching, spiritual guidance and the service of religion.

He was born in 1819 in the village of Pathraita in Sheikhpura District of Bihar. He belonged to the lineage of Hazrat Syed Jamaluddin Jajneri, whose shrine is located at Jamuara in Sheikhpura and was also a descendant of Hazrat Syed Ahmad Jajneri Wasti, whose shrine is situated at Nadiyawan in present-day Lakhisarai District. His father, Mir Amjad Ali Jajneri, was a respected landowner, while his grandfather, Mir Niyaz Ali Jajneri, owned extensive estates. The family was renowned for its religious standing, scholarly tradition, piety and social prestige.

After completing his early education, he travelled to Firangi Mahal, one of the foremost centres of Islamic learning in the Indian subcontinent during the nineteenth century. There he pursued the Dars--e-Nizami curriculum, studying Tafsir, Hadith, Fiqh, Ilm al-Kalam, Arabic language and literature, logic, philosophy, and other traditional Islamic sciences.

His brother Hazrat Sakhawat Hussain Qadri, was also a graduate of Firangi Mahal. Another brother, Hazrat Shuja'at Hussain, became well known for his religious commitment and philanthropic works. He dedicated several properties as waqf, including the land on which the mosque in Pathraita village stands.

Upon completing his education, Maulana Mir Abdullah returned to Bihar and devoted himself to teaching, religious instruction, social reform, and spiritual training. His profound learning, piety, asceticism, and exemplary character attracted students and disciples from distant regions. Among his notable disciples was Rao Abdul Rahman Khan of Mircha Raj, Jamui, who accepted him as his Murshid and as a mark of devotion, even changed his name.

He married Bibi Nasiran, daughter of Mir Irshad Hussain, popularly known as Mir Gaango, who served as the Honorary Magistrate of Munger. They had two sons, Hafiz Mir Abdul Aziz (1863–1919), who married Bibi Jamalan of Jamwara and Mir Muhammad Abdul Jabbar.

Besides being a distinguished teacher and spiritual mentor, Maulana Mir Abdullah was also a prolific author. He wrote numerous books and treatises on Islamic theology, jurisprudence, ethics, Sufism, and religious education. Rather than seeking publication, however, he preferred to distribute handwritten copies of his works among his students. As a result, most of his writings were gradually lost over time and are no longer extant.

Maulana Mir Abdullah passed away in 1882 at Urain, Lakhisarai, where he was laid to rest.

Although most of his scholarly works have not survived, his intellectual and spiritual legacy continues through his descendants and students. In the religious and intellectual history of Bihar.