Dalsinghsarai is a city and Municipal Council in the Samastipur District of Bihar, India.

Alok Kumar Mehta is the Member of the Legislative Assembly of Ujiyarpur constituency and Nityanand Rai is the Member of Parliament of Ujiyarpur.

The city was the center of indigo cultivation during British rule.

In 1902, An Indigo Research Institute was opened nearby in Pusa.

[3] As of 2011[update] India census,[4] Dalsinghsarai Nagar Parishad has population of 55,562 of which 28,402 are males while 27,160 are females as per report released by Census India 2011.