Orhei takes its name from the medieval city of Old Orhei, about 10 miles (16 km) below the modern city on the Răut River, which was destroyed by the Crimean Tatars in the 14th to 16th centuries. It was the Turkish military center of northern Bessarabia until it was taken by the Russian Empire in 1812. The word "orhei" was used by local population, meaning "strengthened hill, fortress, deserted courtyard"
Like the rest of Bessarabia, Orhei became part of the Kingdom of Romania after World War I and was annexed by the USSR in 1940. It was completely destroyed during the Jassy–Kishinev Offensive of August 1944 and was rebuilt after the war. In 1991 it became part of the Republic of Moldova.
Prior to 2003, Orhei was the capital of Orhei County, a large administrative region, but the country was divided further in Raion, or districts.
The St. Dumitru Church built by Vasile Lupu is located in this town. Orhei gets its name from Orheiul Vechi, an active monastery near the village of Ivancea.
The name "Orhei" is, according to one theory, derived from the Hungarian word Őrhely, meaning "lookout post", dating from the 13th century, when Hungarian forces built a series of defences in the area.