- Jack AbbottConstituency: IpswichParty: Labour (Co-op)
- Jack RankinConstituency: WindsorParty: Conservative
- Jacob CollierConstituency: Burton and UttoxeterParty: Labour
- Jade BotterillConstituency: Ossett and Denby DaleParty: Labour
- Jake RichardsConstituency: Rother ValleyParty: Labour
- James AsserConstituency: West Ham and BecktonParty: Labour
- James CartlidgeConstituency: South SuffolkParty: Conservative
- James MacClearyConstituency: LewesParty: Liberal Democrat
- James McMurdockConstituency: South Basildon and East ThurrockParty: Independent
- James MurrayConstituency: Ealing NorthParty: Labour (Co-op)
- James NaishConstituency: RushcliffeParty: Labour
- James WildConstituency: North West NorfolkParty: Conservative
- Jamie StoneConstituency: Caithness, Sutherland and Easter RossParty: Liberal Democrat
- Janet DabyConstituency: Lewisham EastParty: Labour
- Jas AthwalConstituency: Ilford SouthParty: Labour
- Jayne KirkhamConstituency: Truro and FalmouthParty: Labour (Co-op)
- Jeff SmithConstituency: Manchester WithingtonParty: Labour
- Jen CraftConstituency: ThurrockParty: Labour
- Jenny Riddell-CarpenterConstituency: Suffolk CoastalParty: Labour
- Jeremy CorbynConstituency: Islington NorthParty: Your Party
- Jerome MayhewConstituency: Broadland and FakenhamParty: Conservative
- Jess AsatoConstituency: LowestoftParty: Labour
- Jess Brown-FullerConstituency: ChichesterParty: Liberal Democrat
- Jess PhillipsConstituency: Birmingham YardleyParty: Labour
- Jesse NormanConstituency: Hereford and South HerefordshireParty: Conservative
- Jessica MordenConstituency: Newport EastParty: Labour
- Jessica ToaleConstituency: Bournemouth WestParty: Labour
- Jim AllisterConstituency: North AntrimParty: Traditional Unionist Voice
- Jim DicksonConstituency: DartfordParty: Labour
- Jim McMahonConstituency: Oldham West, Chadderton and RoytonParty: Labour (Co-op)
- Jim ShannonConstituency: StrangfordParty: Democratic Unionist Party
- Jo PlattConstituency: Leigh and AthertonParty: Labour (Co-op)
- Jo StevensConstituency: Cardiff EastParty: Labour
- Jo WhiteConstituency: BassetlawParty: Labour
- Joani ReidConstituency: East Kilbride and StrathavenParty: Labour
- Jodie GoslingConstituency: NuneatonParty: Labour
- Joe MorrisConstituency: HexhamParty: Labour
- Joe PowellConstituency: Kensington and BayswaterParty: Labour
- Joe RobertsonConstituency: Isle of Wight EastParty: Conservative
- Johanna BaxterConstituency: Paisley and Renfrewshire SouthParty: Labour
- John CooperConstituency: Dumfries and GallowayParty: Conservative
- John FinucaneConstituency: Belfast NorthParty: Sinn Féin
- John GlenConstituency: SalisburyParty: Conservative
- John GradyConstituency: Glasgow EastParty: Labour
- John HealeyConstituency: Rawmarsh and ConisbroughParty: Labour
- John LamontConstituency: Berwickshire, Roxburgh and SelkirkParty: Conservative
- John McDonnellConstituency: Hayes and HarlingtonParty: Labour
- John MilneConstituency: HorshamParty: Liberal Democrat
- John SlingerConstituency: RugbyParty: Labour
- John WhitbyConstituency: Derbyshire DalesParty: Labour
- Jon PearceConstituency: High PeakParty: Labour
- Jon TrickettConstituency: Normanton and HemsworthParty: Labour
- Jonathan DaviesConstituency: Mid DerbyshireParty: Labour
- Jonathan HinderConstituency: Pendle and ClitheroeParty: Labour
- Jonathan ReynoldsConstituency: Stalybridge and HydeParty: Labour (Co-op)
- Josh BabarindeConstituency: EastbourneParty: Liberal Democrat
- Josh DeanConstituency: Hertford and StortfordParty: Labour
- Josh Fenton-GlynnConstituency: Calder ValleyParty: Labour
- Josh MacAlisterConstituency: Whitehaven and WorkingtonParty: Labour
- Josh NewburyConstituency: Cannock ChaseParty: Labour
- Joy MorrisseyConstituency: BeaconsfieldParty: Conservative
- Judith CumminsConstituency: Bradford SouthParty: Labour
- Julia BuckleyConstituency: ShrewsburyParty: Labour
- Julia LopezConstituency: Hornchurch and UpminsterParty: Conservative
- Juliet CampbellConstituency: BroxtoweParty: Labour
- Justin MaddersConstituency: Ellesmere Port and BromboroughParty: Labour