Alconbury is a village and civil parish in Cambridgeshire, England. Alconbury is situated within Huntingdonshire which is a non-metropolitan district of Cambridgeshire as well as being an historic county of England. Alconbury lies approximately 5 miles (8 km) north-west of Huntingdon.

Alconbury was listed as Acumesberie and Almundeburie in the Hundred of Leightonstone in Huntingdonshire in the Domesday Book of 1086. There was one manor 17.5 households at Alconbury. The survey records that there were 18 ploughlands with the capacity for a further two, and 80 acres (32 hectares) of meadows.

St Peter and St Paul's church is dedicated to St Peter and St Paul. The Great North Road passed through the village and Alconbury Weston to the north-west. The A1 was dualled from Water Newton to Alconbury Hill in three stages in 1958. The two mile A1 bypass opened in December 1964, joining the road at the point where it now meets the A14 (former A604) at the junction at the top of a hill. It followed part of the former A604. In November 1998, the bypass was converted into the A1(M) which terminates next to the village. The former road is partly the B1043 which is also part of the former A14 and the rest of the former A1 to Peterborough. Units of the US Air Force were based at Alconbury from 1942 to 1945, and then from 1953 to 1995.