Lakhisarai district is one of the thirty-eight districts of Bihar state, India, and Lakhisarai town is the administrative headquarters of this district. Lakhisarai district is a part of Munger Division. The district occupies an area of 1228 km2. The district has a population of 8,01,173 (2001 census).

On July 3, 1994 this district was carved out from Munger district, which comprised the erstwhile Lakhisarai sub-division of the undivided district.

Lakhisarai district occupies an area of 1,228 square kilometres (474 sq mi), comparatively equivalent to Papua New Guinea’s New Hanover Island.

In 2006 the Ministry of Panchayati Raj named Lakhisarai one of the country’s 250 districts (out of a total of 640).It is one of the 36 districts in Bihar currently receiving funds from the Backward Regions Grant Fund Programme (BRGF).

According to the 2011 census Lakhisarai district has a population of 1,000,717, roughly equal to the nation of Fiji or the US state of Montana.This gives it a ranking of 445th in India (out of a total of 640).The district has a population density of 815 inhabitants per square kilometre (2,110/sq mi).Its population growth rate over the decade 2001-2011 was 24.74%.Lakhisarai has a sex ratio of 900 females for every 1000 males, and a literacy rate of 64.95%.