There are four new MPs in Hertfordshire, but only one represents a change of party:
- In St Albans, Liberal Democrat Daisy Cooper has taken the seat from Conservative Anne Main
- Conservative Gagan Mohindra held the seat of South West Hertfordshire, despite a challenge from former Tory MP for the seat David Gauke, who had the whip removed after he voted against the government and stood as an independent
- In Hertford and Stortford, Conservative candidate Julie Marson has held the seat for the Tories after Mark Prisk stood down
- In Watford, Dean Russell has been elected MP for Watford, meaning that the Conservative Party holds the seat with an increased majority. He beat Labour's Chris Ostrowski by 4,433 votes, more than double Richard Harrington’s 2,092 vote majority in 2017
- Elsewhere, all the Conservative candidates held their seats. Oliver Heald held Hertfordshire North East, Transport Secretary Grant Shapps retained his seat of Welwyn Hatfield, Bim Afolami held Hitchin and Harpenden, Stephen McPartlandwas re-elected as the MP for Stevenage.
- In Hertsmere, Oliver Dowden has been re-elected, Sir Mike Penning has held Hemel Hempstead and in Broxbourne, Charles Walker has held his seat. .