Hillerød is a Danish town with a population of 33,703 (1 January 2021) located in the centre of North Zealand approximately 30 km to the north of Copenhagen, Denmark. Hillerød is the administrative centre of Hillerød Municipality and also the administrative seat of Region Hovedstaden (Capital Region of Denmark), one of the five regions in Denmark. It is most known for its large Renaissance castle, Frederiksborg Castle, now home to the Museum of National History. Hillerød station is the terminus of one of the radials of the S-train network as well as several local railway lines. The town is surrounded by the former royal forests of Gribskov to the north and Store Dyrehave to the south.

The best known monument is Frederiksborg Castle, which was long a seat of Danish kings. The castle is open to the public and houses the Frederiksborg Museum/ The Museum of National History. The castle also has a large baroque garden.

The Town Museum ("Bymuseet") contains a permanent exhibition on the history of Hillerød.

"The Boiler Room" ("Kedelhuset") has changing special exhibits. In 2005, the subject was the ancient and medieval history of Northern Zealand.

The ruins of Æbelholt Abbey (Æbelholt Klosterruin) are the remains of the largest Augustinian monastery in the northern countries. The site also contains a museum showing its history. The monastery was founded in 1175/76 by the French Augustinian, William of Æbelholt, later Saint William, for the reform of the already extant Eskilsø Abbey, which was moved here. He was summoned to the task by the Danish archbishop and statesman Absalon. After the Reformation in 1536, the monastery lands were appropriated by the state and the buildings were torn down. Some of the bricks were later used in the construction of Frederiksborg Castle.

Esrum Abbey ("Esrum Kloster") is a Cistercian monastery dating from 1151. The only remaining building of this once vast complex now houses a permanent exhibition about the Cistercians. There is a restaurant in the vaults. Next to the monastery is "Esrum Møllegaard", the Nature and Environmental Centre of Ecology.

Another cultural institution is "Hillerød Viden- og Kulturpark" (Hillerød Knowledge and Culture Park); a library with surrounding culture workshops and game spots. This is the gathering spot for the cultural life of Hillerød - with exhibitions, music and theatre.