(originally Raghae), a city in Iran, 8 km southeast of Tehran. Population, 103,000 (1966). The city has a well-developed food industry.

Rey is mentioned in the Avesta and the Behistun inscription. The city was the spring residence of the Parthian kings. In the period 639–644 it was conquered by the Arabs. In the early tenth century. Rey was part of the Samanid state and then part of the Ziyarid dynasty. In 935 the city became part of the Buyid state. Rey was one of tenth-century Iran’s largest cities and most important commercial and artisan centers. It was called the ornament of the Islamic countries. The city was famous for its fabrics, wooden articles, and ceramic and copper wares. It was also known for its library.

In the early 11 th century, Rey was ruled by the Gaznavids, and in 1042 it became the Seljuk residence. In the late 12th and early 13th centuries the city belonged to the Khwarazm shahs. It was overrun by the Mongols in 1220.

An American archaeological expedition conducted from 1934 to 1936 established that an Aeneolithic settlement was initially located on the present-day site of Rey. Remains of structures from the Parthian, Sassanid, and Seljuk periods have been discovered. Lusterware with narrative and ornamental painting was produced in Rey.