Hardoi district is a district of Uttar Pradesh, India, and Hardoi town is the district headquarters. Hardoi district is a part of Lucknow division.

In 2006 the Ministry of Panchayati Raj named Hardoi one of the country’s 250 most backward districts (out of a total of 640).It is one of the 34 districts in Uttar Pradesh currently receiving funds from the Backward Regions Grant Fund Programme (BRGF).

According to the 2011 census Hardoi district has a population of 4,091,380, roughly equal to the nation of Lebanon or the US state of Oregon.This gives it a ranking of 51st in India (out of a total of 640).The district has a population density of 683 inhabitants per square kilometre (1,770/sq mi).Its population growth rate over the decade 2001-2011 was 20.39%.Hardoi has a sex ratio of 856 females for every 1000 males, and a literacy rate of 68.89%.

In 1901, the population of Hardoi district was 1,092,834 and Hardoi had 12,174 inhabitants. By the time, the main city was Shahabad with 20,036 inhabitants, Mallanwan 11,158.