Radlett is located in the council district of Hertsmere and is covered by two wards, Aldenham East and Aldenham West. It is close to St Albans as well as Bushey, Barnet, Borehamwood and Elstree. It is 4 miles North East of Watford. Radlett lies close to the M25 and M1 motorways and the A1 trunk road. Radlett lies in the valley of Tykes Water, a stream that runs north from Aldenham Reservoir to the River Colne.