Mohiuddin Nagar is a block and a notified area in Samastipur district in the Indian state of Bihar, India.

It derives its name from Sufi saint Shah Afaq Mohiuddin.

There is a fort named Amina Bibi ka Quila commonly known as Fansighar.

She was the wife of Shah Afaq and daughter of rebel Afghan general Shamsher Khan who was killed in battle of Ranisarai with Nawab Alivardi Khan.

Government High School, Mohiuddin Nagar There is famous ~ more than 200 years old pipal tree situated in middle market near post office.