| 1 | Bowers HouseAL5 2SG | Grade II* |
| 2 | Harpenden Hall (District Council Offices)AL5 1TE | Grade II* |
| 3 | Moat House HotelAL5 1FA | Grade II* |
| 4 | Parish Church of St NicholasAL5 2TP | Grade II* |
| 5 | 15 and 16, West CommonAL5 2FL | Grade II |
| 6 | 1 and 2, Ayres End LaneAL5 1AN | Grade II |
| 7 | 20, Leyton RoadAL5 2HU | Grade II |
| 8 | 2, Luton RoadAL5 4ET | Grade II |
| 9 | 2, Southdown RoadAL5 2TR | Grade II |
| 10 | 3 and 4, Ayres End LaneAL5 1AN | Grade II |
| 11 | 41, High StreetAL5 2SD | Grade II |
| 12 | 66, 68 68a and 70, High StreetAL5 2SN | Grade II |
| 13 | 69, High StreetAL5 2SL | Grade II |
| 14 | 71, 71a and 73, High StreetAL5 2SL | Grade II |
| 15 | 72 and 72a, High StreetAL5 2SP | Grade II |
| 16 | Church Farm CottageAL5 2TG | Grade II |
| 17 | Coach Lane CottageAL5 2JB | Grade II |
| 18 | Ferrum House with Garage, Terrace and PoolAL5 1DB | Grade II |
| 19 | Flowton PrioryAL5 2JW | Grade II |
| 20 | Garden Wall, Gateposts and Gates Enclosing Front Garden at Harpenden HallAL5 1TE | Grade II |
| 21 | Harpenden LodgeAL5 2UQ | Grade II |
| 22 | Milepost Opposite Moreton End LaneAL5 2UE | Grade II |
| 23 | No. 15 Leyton RoadAL5 2BS | Grade II |
| 24 | Number 1 Thatched CottagesAL5 2JR | Grade II |
| 25 | Railway Bridge Over Southdown RoadAL5 1QN | Grade II |
| 26 | Rivers Lodge (Rothamsted Experimental Station) (Including Front Railings)AL5 2JD | Grade II |
| 27 | Roman Catholic Church of Our Lady of Lourdes, and Associated Gate Piers and RailingsAL5 2BY | Grade II |
| 28 | Royal British Legion Branch Club HeadquartersAL5 2HU | Grade II |
| 29 | The CedarsAL5 1PD | Grade II |
| 30 | The Cross Keys Public HouseAL5 2SD | Grade II |
| 31 | The Dene (Including Front Wall and Railings)AL5 1PD | Grade II |
| 32 | The Harpenden Methodist ChurchAL5 2RU | Grade II |
| 33 | The Inn on the GreenAL5 2BS | Grade II |
| 34 | The Old HouseAL5 2JF | Grade II |
| 35 | The White Horse Public HouseAL5 2JP | Grade II |
| 36 | Three Horseshoes Public HouseAL5 1AW | Grade II |
| 37 | Tollgate CottageAL5 2SL | Grade II |
| 38 | War MemorialAL5 2TN | Grade II |
| 39 | Wellington HouseAL5 2TL | Grade II |