Vavuniya District is one of the 25 districts of Sri Lanka, the second level administrative division of the country. The district is administered by a District Secretariat headed by a District Secretary (previously known as a Government Agent) appointed by the central government of Sri Lanka. The capital of the district is the city of Vavuniya.

Between 5th century BC and 13th century AD present day Vavuniya District was part of Rajarata. Vavuniya District was thereafter ruled by Vanniar Chieftains who paid tribute to the pre-colonial Jaffna kingdom.The district then came under Portuguese, Dutch and British control. In 1815 the British gained control of the entire island of Ceylon. They divided the island into three ethnic based administrative structures: Low Country Sinhalese, Kandyan Sinhalese and Tamil. The district, which was then called Vanni District, was part of the Tamil administration. In 1833, in accordance with the recommendations of the Colebrooke-Cameron Commission, the ethnic based administrative structures were unified into a single administration divided into five geographic provinces.Vanni District, together with Jaffna District and Mannar District, formed the new Northern Province.

Vanni District was later renamed Mullaitivu District and then Vavuniya District. At the time that Ceylon gained independence, Vavuniya was one of the three districts located in the Northern Province. Mullaitivu District was carved out of the northern part of Vavuniya District in September 1978.