Kythrea (Greek: Κυθρέα or Κυθραία; Turkish: Değirmenlik) is a small town in Cyprus, 10 km northeast of Nicosia. Kythrea is under the de facto control of Northern Cyprus.

Kythrea is situated near the ancient Greek city-kingdom of Chytroi, which was founded by Chytros, son of Alexander and grandson of the grandson of the Athenian King Akamas. According to one tradition, the name Kythrea derives from Chytroi (Χύτροι > *Χυτρέα > Κυθρέα). According to another tradition, it derives from the name of the Greek Ionian island Kythera, from where millstones were transferred to Kythrea's watermills. In Delphic Theorodochoi inscription, one inscription mentions the Chytroi.

The small town was watered for millennia by the Kefalovrysos spring; however, shortly after the 1974 Turkish invasion, the water stopped flowing. Other forms of the name include Chytri, Cythraia, Cythereia, Cythroi, Chytrides, Chytros and Chytria.

With the spread of Christianity in Cyprus, Chytroi became a bishopric. The first bishop, whose name is known is Pappus, is mentioned in the Life of Epiphanius of Salamis as having been bishop for 58 years of the "miserable town of Chytria", and as having died a martyr at some unspecified date, which must have been under either the pagan emperors Licinius or Maximinus II, or the Arian Constantius II. The acts of the Council of Chalcedon (451) show that Bishop Photinus was represented there by his deacon Dionysius, and those of the Second Council of Nicaea in 767 that Bishop Spyridon attended in person.

Contemporary documents are lacking concerning Demetrianus, whom Henri Grégoire described as perhaps the most obscure of the local saints of Cyprus. The medieval Leontios Machairas is the earliest writer to make even a brief mention of his name. According to the oldest Life of Demetrianos, published in the 18th century, he became bishop in around 885, was captured by Arabs and taken to Egypt with many of his faithful, but by his prayers obtained the liberation of all.

No longer a residential bishopric, Chytri is today listed by the Catholic Church as a titular see.

Kythrea is a remarkable archaeological area. One outstanding statue discovered in the area is the bronze statue of Roman Emperor Septimius Severus, exhibited in the Cyprus Museum in Nicosia.

In the Middle Ages, Kythrea hosted flourmills that belonged to the King of Cyprus, powered by its water springs. At the end of the 13th century, flour produced in the Kythrea mills provided the supply for the production of bread in the capital, Nicosia.

The Kythrea municipality was established in 1915.

The town is administered by the Turkish Cypriot Municipality of Değirmenlik founded in 1975. The current mayor is Ali Karavezirler from the Republican Turkish Party (CTP). He was elected to the post in 2018, garnering 54.1% of the votes. He replaced Osman Işısal, the mayor elected in 2014 from the same party.

Displaced inhabitants of Kythrea, now located in Nicosia and elsewhere, maintain a municipality in exile. It shares premises with the similarly-displaced municipality of Lapithos at 37 Ammochostou Street, Nicosia.

After its Greek Cypriot inhabitants were displaced in August 1974, the town was repopulated by displaced Turkish Cypriots. The main origin of the Turkish Cypriots that settled in the town is the village of Alaminos, but inhabitants of many other villages were also relocated here. There are some Turkish people that have settled in the town as well, mostly hailing from the Mersin Province.

Prior to the Turkish invasion of Cyprus, Kythrea was the home of the football club AEK Kythreas. Değirmenlik Environment and Publicity Association was founded in 2008. Değirmenlik Association of Culture and Arts is a non-governmental organization that is active in the town, and it annually organizes the Festival of Culture and Arts since 2009. The members of the association participate in festivals abroad. The Municipality of Değirmenlik has a folklore group that is open to children.

Değirmenlik Sports Club was founded in 1975, and now in Cyprus Turkish Football Association (CTFA) K-PET 1st League. Kythrea's Sadik Cemil Football Stadium has "FIFA Recommended Star 2"-standard.

The town is home to Değirmenlik High School.

Kythrea is twinned with:

• Gebze, Kocaeli, Turkey (since 1996)
• Canik, Samsun, Turkey (since 2015)