+Population of Vilnius, 1530–1914Juozas Jurginis; Vytautas Merkys; Adolfas Tautavičius (1968). Vilniaus miesto istorija [Vilnius city history] (in Lithuanian). Vilnius. Year Population 1530 30,0001654 14,0001766 60,0001795 17,7001800 31,0001811 56,3001818 33,6001834 52,3001861 60,5001869 64,4001880 89,6001886 103,000 1897 154,5001900 162,6001911 238,6001914 214,600The demographic history of the Vilnius region encompasses population changes, as well as migration and assimilation processes that have taken place in the region over the centuries.

The Vilnius Region formed part of the Grand Duchy of Lithuania from the emergence of the Lithuanian state in the late Middle Ages until the Third Partition of Poland in 1795, when the Grand Duchy ceased to exist. Following the partitions of the Polish–Lithuanian Commonwealth, the region was incorporated into the Russian Empire, where it remained until its occupation by the German Empire during World War I in 1915.

After the collapse of the Russian Empire and the end of the war, Vilnius and its surrounding region became the subject of competing territorial claims by the newly established Republic of Lithuania and the Second Polish Republic. Finally the region was incorporated into Poland in 1922 and remained part of the Polish state throughout the Interwar period. Lithuania, however, continued to regard Vilnius as its de jure capital and did not recognize Polish sovereignty over the region.

In 1939, the region was occupied by the Soviet Union and transferred to Lithuania under the Soviet–Lithuanian Mutual Assistance Treaty. Following the Soviet annexation of Lithuania in 1940, it became part of the Lithuanian Soviet Socialist Republic. The region was occupied by Nazi Germany from 1941 to 1944, during which most of its Jewish population perished in the Holocaust. Reoccupied by the Soviet Union in 1944, it remained part of the Lithuanian Soviet Socialist Republic until 1990. Following the dissolution of the Soviet Union and the restoration of Lithuanian independence in 1990–1991, the Vilnius Region became part of the modern Republic of Lithuania.

Census data for the Vilnius Region are available from 1897 onward, although comparisons over time are complicated by changes in administrative boundaries, and ethnic classifications. The region's demographic structure underwent profound changes during the 20th century. The Jewish population, was largely annihilated during the Holocaust between 1941 and 1944. After World War II, a substantial part of the Polish population of Vilnius was resettled to post-war Poland, while the Polish population remained comparatively numerous in the surrounding rural areas. At the same time, migration from other parts of Lithuania and the Soviet Union contributed to the growth of the Lithuanian population in the city. As a result, recent census data show Lithuanians forming the majority population in the city of Vilnius, whereas Poles remain the largest ethnic group in the surrounding Vilnius District Municipality.

Ethnic and national background Already in the 1st century, Lithuanian tribes inhabited Lithuania proper. Slavicisation of Lithuanians in eastern and southeastern Lithuania began in the 16th century. It is recorded that in 1554, Lithuanian, Polish and Church Slavonic were spoken in Vilnius. The Statutes of Lithuania, officially enforced from 1588 until 1840, forbid Polish nobility to buy estates in Lithuania, hence a mass migration of Poles into the Vilnius region was impossible. The Lithuanian nobility and Bourgeoisie was gradually Polonized over the 17th and 18th centuries.

Until the end of the 19th century, Peasants in eastern Lithuania proper were Lithuanians. This is attested by their un-Polonized surnames, and most Lithuanians in eastern Lithuania proper were Slavicized by schools and churches in the last quarter of the 19th century.

Polonization resulted in the mixed language spoken in the Vilnius region by Tutejszy, where it was known as "mowa prosta". It is not recognized as a dialect of Polish and borrows heavily from the Polish, Lithuanian and Belarusian languages. According to Polish professor Jan Otrębski's article published in 1931, the Polish dialect in the Vilnius Region and in the northeastern areas in general are very interesting variant of Polishness as this dialect developed in a foreign territory which was mostly inhabited by the Lithuanians who were Belarusized (mostly) or Polonized, and to prove this Otrębski provided examples of Lithuanianisms in the Tutejszy language. In 2015, Polish linguist Mirosław Jankowiak attested that many of the region's inhabitants who declare Polish nationality speak a Belarusian dialect which they call mowa prosta ('simple speech').

According to recent ethnographic research by Yury Vnukovich (2023), this situation represents an "ethnic anomaly": while local Lithuanians are identified primarily by their language, for the local Slavic-speaking population, their everyday language ("prostaya mova") is not a marker of ethnicity. Instead, residents identify as Poles based on other factors, primarily their Catholic faith (locally perceived as the "Polish faith") and their origin from the region. Vnukovich notes that "prostaya mova" is often stigmatized by its speakers as "uneducated," whereas standard Polish holds high prestige as a symbol of their identity, even if they do not speak it fluently in daily life.

Ancient period In the eldership of Vilkpėdė, remnants of a Magdalenian settlement were found which date to . The confluence of the Neris and Vilnia was densely inhabited by the Brushed Pottery culture at , which had a half-hectare fortified settlement on Gediminas' Hill. Tribes of this culture inhabited present-day Lithuania east of the Šventoji River and in western Belarus. The descendants of this culture were a Baltic tribe, the Aukštaitians (). According to historian Antanas Čaplinskas, who researched the surnames of Vilnius residents, the city's oldest surviving surnames are Lithuanian. Pagan Lithuanians primarily lived at the northern foot of Gediminas' Hill and in the Crooked Castle. Kairėnai, Pūčkoriai and Naujoji Vilnia had large settlements during the first millennium AD. The most densely populated area was the confluence of the Neris and Vilnia, which had fortified homesteads.

Medieval period Vilnius was part of the Kingdom of Lithuania; King Mindaugas did not permanently live there, however, despite building Lithuania's first Catholic church for his coronation. The city began to develop in the late 13th century, during the reign of Grand Dukes Butvydas and Vytenis.Vilnius' growth is attributed to Grand Duke Gediminas, who invited knights, merchants, doctors, craftspeople and others to come to the duchy to practice their trades and religion without restriction during the 14th century. However, the city's growth was limited by Teutonic Order attacks and the 1389–1392 Lithuanian Civil War. Invited by Grand Duke Gediminas, merchants and craftsmen began moving to Vilnius from the cities of the German Hanseatic League, France, Italy and Spain; Lithuanian surnames were replaced with German, Polish, and Russian ones. In the late 14th century, during the reign of Grand Duke Algirdas, Vilnius had a Ruthenian quarter () in present-day Latako and Rusų Streets. Trade between the Grand Duchy of Lithuania and the Ruthenian principalities was well-developed, with Ruthenian merchants and Ruthenian nobility living in the quarter. Vilnius' multiculturalism was increased by Grand Duke Vytautas the Great, who introduced Litvaks, Tatars and Crimean Karaites. After several centuries, the number of local residents in Vilnius was smaller than the number of newcomers. However, according to an analysis of the 1572 tax registers, Lithuania had 850,000 residents; 680,000 were Lithuanians.

Early modern period It became a multicultural city, with 14th-century sources noting that it consisted of a Great (Lithuanian) city and a Ruthenian one. By the 16th century, German merchants, artisans, Jews and Tatars had also settled in Vilnius. During the 16th– and 17th-century Reformation and Counter-Reformation, the city's Polish-speaking population began to grow; by the middle of the 17th century, most writing was in Polish.

During the Lithuanian Golden Age, Vilnius was a major city in the Polish–Lithuanian Commonwealth and home to the Lithuanian nobility; however, it was severely damaged by a 1610 fire. By the middle of the 17th century, most Lithuanian upper nobility was Polonized. Over time, the nobility of the former Polish–Lithuanian Commonwealth unified politically and started to consider themselves to be citizens of one common state.

After the 1655 Battle of Vilnius the city was under Russian control until 1661. During the Great Northern War, the Swedish Empire controlled Vilnius from 1702 to 1709. The occupation ended with the Great Northern War plague outbreak, and the city took over 50 years to recover. According to historian Vytautas Merkys, the city lost much of its old population under Swedish and Russian domination during the 17th and 18th centuries; although they were replaced by newcomers, Lithuanians continued to live in Vilnius.

After the partitions of Polish–Lithuanian Commonwealth

According to the first Commonwealth census in 1790, the Vilnius Voivodeship had a population of 718,571 and Vilnius County had 105,896 residents; after the Second Partition, the Grand Duchy had a population of 1,333,493. The city's population fell to 17,500 in 1796 due to the 1794 Kościuszko Uprising, the last attempt to save it from Russian control. Vilnius was incorporated into the Russian Empire, and was its third-largest city at the beginning of the 19th century. The city was again affected by the 1830 November Uprising and the January Uprising in 1863.

Following the failed November uprising all traces of former Polish–Lithuanian statehood (like the Third Statute of Lithuania and Congress Poland) were replaced with Russian counterparts, ranging from the currency and units of measurement to offices of local administration. The failed January Uprising of 1863–64 further aggravated the situation, as the Russian authorities decided to pursue the policies of forcibly imposed Russification. The discrimination of local inhabitants included restrictions and bans on usage of Lithuanian (see Lithuanian press ban), Polish, Belarusian and Ukrainian (see Valuev circular) languages.

According to the 1897 Russian census, Vilnius had a population of 154,532 residents and the Vilna Governorate had 1,561,713. Vilnius' population became ethnically less Lithuanian. In the Russian census of 1897, 2.1 percent identified as Lithuanian speakers; speakers of Polish (30.8% percent) and Yiddish (40 percent) were the city's largest linguistic groups. According to parish censuses in 1857–1858, the Lithuanian population was between 23.6 and 50 percent in the Vilna Governorate. In 1863, ethnographer Roderich von Erckert identified the governorate's largest ethnic group as Lithuanians (45.04 percent). Among the szlachta (nobility) in Vilnius in the 1897 census were 5,301 (46 percent) local nobles and 6,403 (54 percent) newcomers; of the newcomers, 24.1 percent were from the Vilna Governorate and the remainder from Grodno, Minsk, Vitebsk and Kovno Governorates, Vistula Land and other regions.