Accurate or reliable data for historical populations of Armenians is scarce, but scholars and institutions have proposed estimates for different periods.

For most recent data on Armenian populations, see Armenian population by country.

Ancient Tadevos Hakobyan, Elizabeth Redgate, and David Marshall Lang all estimate that historical Armenia's population never exceeded 5 or 6 million, citing factors such as army size, tax records, and the region's largely uninhabitable terrain.

Based on historical records, Igor M. Diakonoff estimated the population of Urartu as having "certainly exceeded one million and may have reached two or three million". He also found 6 to 7 million a "plausible figure." For around 585 BC, John M. Douglas proposed an approximate population of 3 million for Urartu and 2 million for Proto-Armenians.

Ruben L. Manaseryan estimated the population of the short-lived empire of Tigranes the Great () at 10 million. Sedrak Krkyasharyan estimated over 10.5 million people in his empire, including around 4 million Armenians."Демография государства Великая Армения во времена Тиграна II Великого [Demographics of the state of Greater Armenia during the time of Tigran II the Great]", published in Russian on March 25, 2020 by times.am (archived) and voskanapat.info (archived). "численность армянского населения в I в. до н. э. составляла около 4 млн. человек. [...] Таким же образом можно вычислить численность населения державы Тиграна Великого. Оно составляло более 10,5 млн. человек." Earlier estimates by non-historians such as Jacques de Morgan, Isaac Don Levine and Bodil Biørn put it considerably higher, at 25 and 30 million.Bodil Katharine Biørn (1944). Armenia og armenierne (in Norwegian). "Armenia var tidligere et kongerike som var størst under Digranes den store. Han grunnla Digranagerd (Diabekir) og regjerte over 30 mill. mennesker."; published in Kvinnelige misjonsarbeidere, Se til hvorledes i bygger videre, K.M.A. gjennom 50 år (Oslo, 1952); translated into Armenian «Հայաստանը նախկինում թագավորություն է եղել, որն ամենամեծն է եղել Տիգրան Մեծի օրոք։ Նա հիմնել է Տիգրանակերտը (Դիարբեքիր) և կառավարել ավելի քան 30 մլն բնակչության։» Hakob Manandian posited that the population of Armenia during the reigns of Artaxias I and Tigranes II was "much larger than that of later centuries."

Agathangelos wrote that during the Christianization of Armenia in the early fourth century more than 4,000,000 men, women and children and more than 150,000 soldiers (a total of 4,150,000) were baptized by Gregory the Illuminator. Malachia Ormanian and Antranig Chalabian accepted the figure, while Edmond Schütz found the figure for the population of Greater Armenia “obviously exaggerated.” Suren Yeremian proposed 4 million as the population of both Arsacid Armenia and of Armenians.

Medieval Based on tax records, Arsen Shahinyan estimated the population of Arminiya, an administrative unit of the Abbasid Caliphate, in the 8th and 9th centuries at 1.5 million, including 750,000 in Arminiya I (Greater Armenia), around 650,000 in Arminiya II (Arran, i.e. Caucasian Albania), and around 100,000 in Arminiya III (Jurzan, i.e. Eastern Georgia).

Serob Poghosyan estimated Armenia's population in the 9th–11th centuries, when much of it was ruled by the Bagratids, at 5 to 6 million. Kersam Aharonian proposed at least six million by the early 1000s, prior to the Seljuk invasions. Mikayel Malkhasyan estimated Vaspurakan's population in the same period at no less than a million people.

Tadevos Hakobyan suggested that Armenia's population reached 5 to 6 million only in the 13th century, prior to the Mongol invasion, when he estimated 4.5 million people in rural areas and around 500,000 in cities. Others have estimated Armenia's population in the mid-13th century at 4 million. Based on tax records, Manandian estimated the combined population of eastern Armenia, Kars and eastern Georgia (Kartli and Kakheti) in the mid-13th century at 4 to 5 million.Manandian, Hakob. (1952) Քննական Տեսություն Հայ Ժողովրդի Պատմության (Critical View of the History of the Armenian People), vol. 3, Yerevan: Academy of Sciences Press, p. 251 «Ըստ այս վկայության գրանցված հարկատու գյուղացիների թիվը Լաշայի որդի Դավթի ժամանակ ցույց է տրված, ինչպես տեսնում ենք, մոտ մեկ միլիոն մարդ: Ավելացնելով այս թվին նաև երեխաների, ծերերի, կանանց, հոգևորականների և քաղաքացիների թիվը՝ կարելի է ենթադրել, որ վրաց թագավորության բնակչության թիվը 13-րդ դարի կեսերին եղել է 4-5 միլիոն: Այս թիվը, որ կարող էր մոտավորապես ճիշտ լինել՝ վերաբերում է, իհարկե, ոչ միայն Քարթլիի և Կախեթի բնակչությանը, ինչպես այդ հնթադրում է Բրոսսեն, այլ վրաց ամբողջ թագավորությանը, որի մասն էին կազմում այդ ժամանակ նաև Արևելլան Հայաստանը, Կարսը և այլ շրջաններ:». quoted in

Modern Armenian scholars believe that the medieval Armenian Kingdom of Cilicia had a population of around one million, most of whom were Armenians.

19th and early 20th century Estimates Various 19th century scholars, both Western and Armenian, provided estimates for the global Armenian population, with the majority of estimates clustering around 4–5 million.

Russian historian Vladimir Kabuzan (1996) estimated up to 2 million Armenians worldwide by the early 19th century, including 1.6 million in Turkey (including about 100,000 in the European part); about 70,000 in Persia; 3,000 in Egypt, 2,500 in Afghanistan; nearly 13,000 in the Austrian Empire (including 5,800 in Galicia, 1,000 in Hungary, and 5,500 in Transylvania). Of the 133,000 Armenians in the Russian Empire, 107,000 lived in the Transcaucasus before the Russo-Persian War of 1826–28 and Russo-Turkish War of 1828–29. By the 1860s, more than 530,000 Armenians lived in the Russian Empire, of whom nearly 480,000 were in Transcaucasia.

August von Haxthausen quoted Catholicos Nerses V (then archbishop) as having told him in 1843 that he can assert with confidence the existence of more than eight million Armenians worldwide, including 30,000 Catholic Armenians in the Russian Caucasus.

In 1847 John Wilson estimated the total Armenian population at 2.5 million, with 1 million in the Russian Empire, 1 million in the Ottoman Empire and 0.5 million in Persia and "other distant lands." He quoted the figures provided by Lucas Balthazar, the "intelligent editor" of the Smyrna-based Armenian newspaper The Dawn of Ararat, who estimated 5 million Armenians overall, with 2 million in Russia, 2 million in Turkey and 1 million in Persia, India and elsewhere.

The 9th edition of the Encyclopædia Britannica (1875) cited Édouard Dulaurier's estimates : approximately four millions Armenians in the world, including 2,500,000 in the Ottoman Empire, 1,200,000 in the Russian Empire, 25,000 in the Austrian Empire, 150,000 in Persia and Azerbaijan, 25,000 in continental India and the Archipelago of Asia, and the remainder of 100,000 scattered in various countries.

Richard Robert Madden wrote in 1862 that the Armenian population worldwide is estimated at 4 million, of whom an estimated 2,400,000 in the Ottoman Empire ("an approximate computation, and probably below the truth"), 900,000 in the Russian Empire, 600,000 in Persia, 40,000 in India and "other realms of Asia", and 60,000 in "various European countries."

In 1876 John Buchan Telfer, quoted the figures provided by Garabed Ghazarosian in his 1873 The Universal Year Book, which estimated a total of 4.2 million Armenians worldwide, including 2.5 million in Turkish dominions, 1.5 million in Russia, 34,000 in Persia, 14,600 in Austria, 15,000 in England, India and other British possessions, 8,400 in Romania, 8,000 in Egypt, and 120,000 in other countries. archived PDF In 1891, Telfer reported to the Royal Society of Arts that "most authorities" appear to agree that the total Armenian population worldwide amounts to around 5 million, with most "scattered in their own land and in adjoining territories" and nearly half a million "settled in distant parts."

In 1891 Élisée Reclus wrote that while "usually estimated at three and even four millions," the total number of Armenians "would seem scarcely to exceed two millions." He estimated the "probable" number of Armenians as follows: 840,000 in Caucasia and European Russia, 760,000 in Asiatic Turkey, and 250,000 in European Turkey, 150,000 in Persia, and 60,000 elsewhere, with the total at 2,060,000. He estimated no less than 200,000 Armenians in Constantinople and noted that Tiflis held the second largest Armenian population of any city.

At the 1893 Parliament of the World's Religions, Armenian activist claimed that there were 5.1 million Armenians in total, including 80,000 Catholics and 20,000 Protestants.

Russian-Armenian historian Alexei Dzhivelegov, writing for the Brockhaus and Efron Encyclopedic Dictionary (1911) estimated the total number of Armenians "somewhat under 3 million", including around 1,212,000 in Russia, 1,144,000 in Turkey ("at least prior to the massacres"), 100,000 in Persia, 5,000 in India and Africa each, around 20,000 in Hungary and Galicia, and several thousand in other European states.

Adrian Fortescue wrote in 1916: "There are said to be about three and a half or four million Armenians in the world—1,300,000 in Turkey, 1,200,000 in Russia, 50,000 in Persia, and the rest dispersed throughout the world. Of these about three quarters belong to the Monophysite ("Gregorian") Church."

Ormanian (1911) Malachia Ormanian, a scholar and former Armenian Patriarch of Constantinople, estimated the population of Christian Armenians by the dioceses of the Armenian Apostolic Church in his 1911 book The Church of Armenia. It is the most detailed population distribution estimates available prior to the Armenian genocide. Robert Hewsen wrote that "Ormanian's figures appear moderate and reasonable, although this does not necessarily make them precise." Levon Marashlian notes that "the purpose of Ormanian's book was not to provide comprehensive population statistics" and that "his numbers for [Armenian] Protestants and Catholics may be even more incomplete" than for Armenian Apostolics.

Country/territory Armenians 1,709,550 1,579,500 Persia 83,400 United States 50,000 Western Europe( Great Britain, France, , ) 21,000 Bulgaria 20,000 Egypt 15,500 Romania 10,000 Austria-Hungary 9,000 India and Indochina 6,000 Dutch East Indies 4,000 Greece 1,000 Total 3,508,950 Ottoman Empire

Russian Empire According to the Armenian Soviet Encyclopedia, what is now Armenia (historically known as Eastern Armenia) that came under Russian rule in 1828, had a population of 161,700 in 1831, which rose to 1.01 million by 1913.

According to the Russian Empire census of 1897, there were 1,173,096 native speakers of Armenian in the empire. The religious statistics indicated 1,179,241 Armenian Apostolics ("Gregorians") and 38,840 Catholic Armenians, amounting to a total of 1,218,081. According to official estimates for 1916, published in the Kavkazskiy kalendar, 1,859,663 Armenians lived in Russia's Caucasus Viceroyalty alone. Estimates by John Foster Fraser (1907) and Richard G. Hovannisian (2005) put the number of Armenians within the Russian Empire in the early 20th century at around 2 million. According to official estimates, 1,988,700 Armenians lived in the Russian Empire by 1916.

Post-genocide

1922 The United States Department of State summarized the populations of Armenians in a November 1922 document entitled "Approximate number of Armenians in the world" (NARA 867.4016/816). Of the total 3,004,000 Armenians, 817,873 were refugees from Turkey "based upon information furnished by the British Embassy, Constantinople, and by the agents of the Near East Relief Society, in 1921. The total given does not include the able-bodied Armenians, who are retained by the Kemalists, nor the women and children,—approximately 95,000,—according to the League of Nations-who have been forced to embrace Islam."