Chittoor district () is one of the eight districts in the Rayalaseema region of the Indian state of Andhra Pradesh. It has a population of 18,72,951 according to 2011 census of India. It is a major market centre for mangoes, grains, sugarcane, and peanuts. The district headquarters is located at Chittoor.
The district derived its name from its headquarters Chittoor.
After the Indian independence in 1947, Chittoor region became a part of the erstwhile Madras state. The modern Chittoor district was formerly Arcot District, which was established by the British in the 19th century. It had Chittoor as its headquarters.
Chittoor district was constituted on 1st April, 1911 with the taluks of Chittoor, Palamaner, and Chandragiri from Old North Arcot district of Tamilnadu, Madanapalle and Voyalpadu Taluks of Kadapa district and Ex-Zamindari areas of Pileru, Punganur, Srikalahasthi, Puttur and Old Karvetinagar estate. As a result of Pataskar Award consequent on the re-organisation of the state on linguistic basis on 1st April, 1960, a major portion of Tiruthani taluk was transferred to Chengalpattu district of Tamilnadu in exchange for one taluk known as Sathyavedu comprising 186 villages from Tamilnadu. Also from the same date, the Sub-Taluks of Kuppam and Bangarupalem were constituted transferring 220 villages from Palamaner Taluk and Three villages from Krishnagiri Taluk of Salem District of Tamilnadu to form Kuppam Sub-Taluk and 145 villages from Chittoor Taluk to form Bangarupalem Sub-Taluk. Subsequently, Kuppam and Bangarupalem were made full fledged taluks.The district was organised into 66 revenue mandals in 1985.Again the District Re-organised with 31 Mandals and 4 Revenue Divisions on 4th April, 2022.
Annamayya district and Tirupati district are formed from parts of erstwhile Chittoor district and others. This has resulted in the district becoming primarily rural and losing central educational institutes and health infrastructure.
According to the 2011 census, Chittoor district prior to restructuring in 2022 has a population of 4,174,064.