Siirt (Kurdish: سێرت, romanized: Sêrt; Arabic: سِعِرْد, romanized: Veleye; Armenian: Սղերդ, romanized: S'gherd;^{[citation needed]} Syriac: ܣܥܪܬ, romanized: Siirt;) is a city in the Siirt District of Siirt Province in Turkey. It had a population of 160,340 in 2021. The city is predominantly inhabited by Kurds and is considered part of Turkish Kurdistan.

Previously known as Saird, in pre-Islamic times Siirt was a diocese of the Eastern Orthodox Church (Sirte, Σίρτη in Byzantine Greek). In the medieval times, Arzen was the main city and it competed with Hasankeyf over the control the region, Siirt was only to become a center of the region in the 14th century. But it was still dependent from Hasankeyf until the 17th century. An illuminated manuscript known as the Syriac Bible of Paris might have originated from the Bishop of Siirt's library, Siirt's Christians would have worshipped in Syriac, a liturgical language descended from Aramaic still in use by the Syriac Rite, Chaldean Rite, other Eastern Christians in India, and the Nestorians along the Silk Road as far as China. The Chronicle of Seert was preserved in the city; it describes the ecclesiastical history of the Persian realm through to the middle of the seventh century.

From 1858 to 1915 the city was the seat of a bishop of the Chaldean Catholic Church. Most of the city's Assyrians, including Addai Scher their archbishop were murdered during the Assyrian genocide along with the loss of artefacts such as the Syriac manuscript of Theodore of Mopsuestia's De Incarnatione. Also during World War I, the Armenian population of Siirt became a victim of the Armenian genocide.

Kurdish regions such as Siirt have been under martial law for most periods since 1927 and were included in the OHAL (state of emergency) zone in 1983, prior to the start of the PKK’s armed campaign. During the early stages of the Kurdish–Turkish conflict in the 1990s, former Turkish President Turgut Özal advocated transforming cities like Siirt into “centers of attraction” for the rural Kurdish population, while simultaneously supporting the eviction and destruction of Kurdish villages and hamlets in the surrounding mountains through military operations and dam construction projects.

In wake of the 2014 Kobanî protests, which were part of the broader third phase of the Kurdish–Turkish conflict, local Kurdish youth and activists organized popular protests in the city of Siirt, which led to the death of several protestors due to excessive police violence. The conflict later escalated into a full-scale military confrontation in the city between what the Turkish government described as “PKK and YDG-H militants” and Turkish security forces. This escalation involved the imposition of curfews and the deployment of the Turkish army throughout the area, which was described as a siege by pro-Kurdish media. During the conflict, Turkish forces were targeted in multiple incidents, including the 2015 Siirt bombing, a roadside explosion on a highway near Siirt city in July 2016, rocket attacks in the Cumhuriyet neighborhood, bombings in 2018, the 2018 Siirt raid, and several other attacks, resulting in numerous deaths and injuries.

Mark Sykes recorded Siirt as a city inhabited by Kurds, Arabs, Assyrians, and Armenians. During the second half of the 19th century, many Armenians left Siirt due to persecutions and poor economic conditions. During the 1895 Hamidian massacres, many Armenians were forcibly converted to Islam and the clergy was massacred. Before World War I, the sanjak of Siirt formed a Christian enclave with 60,000 Christians: 25,000 Armenians, 20,000 Syriac Orthodox, and 15,000 Chaldean Catholics. According to the Armenian Patriarchate of Constantinople, in 1914 there were 4,437 Armenians in the kaza, with three churches, one monastery and two schools. Agha Petros mentions 40 Nestorian Assyrian families in the city of Siirt. Mardin Chaldean priest Joseph Tfinkdji lists 5,430 Chaldeans in the diocese: 824 in the town and the rest in surrounding villages. The community was led by Addai Sher. David Gaunt mentions some Yezidi presence.

According to the 1927 census, the population in the whole district was almost exclusively Muslim, with the exception of two Catholics, one Protestant, four Armenians, 17 other Christians, and 38 "other religion".

İsmet İnönü referred to the city as an Arab city eager to get Turkified, while Kurds lived in the outskirts.