Gherla (Romanian pronunciation: [ˈɡerla]; Hungarian: Szamosújvár; German: Neuschloss) is a municipality in Cluj County, Romania (in the historical region of Transylvania). It is located 45 kilometres (28 mi) from Cluj-Napoca on the river Someșul Mic, and has a population of 19,873 as of 2021. Three villages are administered by the city: Băița (formerly Chirău, and Kérő in Hungarian), Hășdate (Szamoshesdát) and Silivaș (Vizszilvás).

The city was formerly known as Armenopolis (Armenian: Հայաքաղաք Hayakaghak; German: Armenierstadt; Hungarian: Örményváros) because it was populated by Armenians.

A clay tablet containing a fragmentary Old Persian cuneiform of the Achaemenid king Darius I was found at Gherla in 1937. It may be connected to Darius I's epigraphic activities in relation to his Scythian campaign of 513 BC as reported by Herodotus.

The locality was first recorded in 1291 as a village named Gherlahida, (probably derived from the Slavic word grle, meaning "ford"). The second name was Armenian (Հայաքաղաք, Hayakaghak) meaning "Armenian city"; it took the Medieval Latin and Greek official name Armenopolis, as well as the German alternative name Armenierstadt. Later, the name Szamosújvár was used in official Hungarian records, meaning "the new town on the Someș".

The modern city was built in the early 18th century by Armenians, successors of the Cilician Armenian diaspora, who had originally settled in Crimea and Moldavia, and moved to Transylvania sometime after 1650. After a two years' campaign by the Armenian-Catholic Bishop Oxendius Vărzărescu, they converted from the Armenian Apostolic Church to the Armenian Catholic Church; an Armenian Catholic cathedral in Gherla was consecrated in 1748.

Gherla is the seat of the Ordinariate for Catholics of Armenian Rite in Romania, as well as that of a Greek-Catholic diocese – the Cluj-Gherla Diocese (suffragan to the Greek-Catholic Archbishop of Alba Iulia and Făgăraș-Blaj, who resided in Blaj). In the center of the city lie the Saint Gregory the Illuminator and the Holy Trinity Armenian Cathedral. The main Armenian-Catholic church was built in 1792. The Greek Catholic diocese was created by the Papal Bull Ad Apostolicam Sedem of November 26, 1853, and the first bishop was Ioan Alexi.

A Habsburg fortress was built here and converted to a prison in 1785. During the Communist regime, the prison was used for political detainees. Today it is a Romanian high-security prison.

During the Years of Revolution of 1848 and 1849, Gherla was the stage for numerous battles between the warring parties, changing hands several times. The Austrian commander Karl von Urban and his Romanian Regiment liberated the city three times from Hungarian revolutionary forces, winning the Battle of Szamosújvár on 13 November 1848, a landmark of the stormy period. Starting in 1867, Gherla was no more part of the Principality of Transilvania and was annexed until 1918, to the Kingdom of Hungary comitatus of Szolnok-Doboka.