1918–1974

• The administrative county of Huntingdonshire.^[2]

1974–1983

In 1965 Huntingdonshire was merged into the new administrative county of Huntingdon and Peterborough and in the next redistribution of parliamentary seats, which took effect for the February 1974 general election, the constituency was defined as comprising:

• The Municipal Boroughs of Huntingdon and Godmanchester, and St Ives:
• The Urban Districts of Old Fletton, Ramsey, and St Neots; and
• The Rural Districts of Huntingdon, Norman Cross, St Ives, and St Neots.^[2]

Eaton Socon in Bedfordshire had been absorbed by the Urban District of St Neots and was transferred from the County Constituency of Mid Bedfordshire.  There were other marginal adjustments due to changes in county borders.

As a result of the Local Government Act 1972, the two counties of Cambridgeshire and Isle of Ely, and Huntingdon and Peterborough were merged to form the non-metropolitan county of Cambridgeshire, with effect from 1 April 1974. However, the next redistribution did not come into effect until the 1983 general election, when the majority of the constituency, including Huntingdon, Godmanchester, Ramsey and St Ives, formed the bulk of the re-established onstituency of Huntingdon. Areas to the south of the River Nene, including Fletton and the Ortons, which were now part of the expanded City of Peterborough, were transferred to Peterborough, and southernmost areas, including St Neots, were transferred to the new constituency of South West Cambridgeshire.

MPs 1660–1885

MPs 1918–1983

Elections in the 1830s

Elections in the 1840s

Elections in the 1850s

Thornhill's death caused a by-election.

Montagu succeeded to the peerage, becoming 7th Duke of Manchester and causing a by-election.

Securing the same number of votes, both Fellowes and Heathcote were returned alongside Rust as Members of Parliament. However, after scrutiny, Rust and Fellowes lost one vote, while Heathcote lost two, causing Heathcote to be declared unduly elected on 31 July 1857.

Elections in the 1860s

Montagu's appointment as Vice-President of the Committee of the Council on Education required a by-election.

Elections in the 1870s

Pelly's death caused a by-election.

Elections in the 1880s

Elections in the 1910s

Elections in the 1920s

Elections in the 1930s

General Election 1939–40

Another General Election was required to take place before the end of 1940. The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;

• Liberal National: Sidney Peters
• Labour: James Lunnon^[15]

Elections in the 1940s

Elections in the 1950s

Elections in the 1960s

Elections in the 1970s