Romsey and Southampton North is a constituency represented in the House of Commons of the UK Parliament since its 2010 creation by Caroline Nokes for the Conservative Party.

2024–present: Further to the 2023 Periodic Review of Westminster constituencies which became effective for the 2024 general election, the constituency is composed of the following (as they existed on 1 December 2020): The boundaries were extended northwards to included rural areas to the south and west of Andover, transferred from North West Hampshire.

The constituency takes in the bulk of a more affluent and older-population local government district with a fraction of a contrasting district: the net result is a working population whose income is close to the national average and lower than average reliance upon social housing.

[4] At the end of 2012, the unemployment rate in the constituency stood as 1.5% of the population claiming Jobseeker's Allowance, compared to the regional average of 2.4%.

In terms of tenure 70.4% of homes are owned outright or on a mortgage as at the 2011 census in Test Valley district.