جمعیت آشوریان ایران در میانهٔ قرن نوزدهم میلادی به ۱۳۸،۰۰۰ نفر میرسید که عمدتاً در آذربایجان غربی ساکن بودند و به دو گروه عمدهٔ مذهبی نستوری و کاتولیک تقسیم میشدند. جمعیت آشوریان ایران در میانهٔ قرن بیستم میلادی به ۲۰،۰۰۰ نفر کاهش پیدا کرد. در سال ۱۳۸۷ نیز جمعیت آشوریان ایران حدود ۲۰،۰۰۰ نفر برآورد شد. 
پس از انقلاب مشروطه، با تشکیل مجلس شورای ملی، در قانون اساسی مشروطه برای اقلیتهای دینی هم نمایندگانی در نظر گرفته شد. از جمله، یک نماینده برای مسیحیان آشوری و کلدانی. این موضوع پس از انقلاب ۱۳۵۷ هم در قانون اساسی باقی ماند. مقر اتحادیه جهانی آشوریها نیز به همراه رئیس این مرکز یوناتن بت کلیا در تهران مستقر هست.
Assyrians in Iran, Iranian Assyrians or Persian Assyrians (Syriac: ܐܬܘܪܝܐ ܕܐܝܼܪܵܢ), (Persian: آشوریان ایران), are an ethnic and linguistic minority in present-day Iran. The Assyrians of Iran speak Assyrian Neo-Aramaic, a neo-Aramaic language descended from Classical Syriac and elements of Akkadian, and are Eastern Rite Christians belonging mostly to the Assyrian Church of the East and also to the Ancient Church of the East, Assyrian Pentecostal Church, Chaldean Catholic Church and Assyrian Evangelical Church.
They share a common history and ethnic identity, rooted in shared linguistic, cultural and religious traditions, with Assyrians in Iraq, Assyrians in Turkey and Assyrians in Syria, as well as with the Assyrian diaspora.
The Assyrian community in Iran numbered approximately 200,000 prior to the Islamic Revolution of 1979. However, after the revolution many Assyrians left the country, primarily for the United States; the 1996 Iranian census counted only 32,000 Assyrians. Current estimates of the Assyrian population in Iran range from 32,000 (as of 2005[update]) to 50,000 (as of 2007[update]).
The Iranian capital, Tehran, is home to the majority of Iranian Assyrians; however, approximately 15,000 Assyrians reside in northern Iran, in Urmia and various Assyrian villages in the surrounding area.
The Constitution of the Islamic Republic of Iran, ratified in 1979, recognizes Assyrians as a religious minority and ethnic minority and reserves for them one seat in the Islamic Consultative Assembly, the Iranian parliament. As of 2004[update], the seat was occupied by Yonathan Betkolia, who was elected in 2000 and reelected in the 2004 legislative election.
Today, scholars estimate that there are only around 5,000 Assyrians left in the historical center of the city of Urmia.
The Assyrian presence in Iran goes back 4,000 years to ancient times, and Assyria was involved in the history of Ancient Iran even before the arrival of the modern Iranian peoples to the region circa 1000 BC. During the Old Assyrian Empire (c.2025-1750 BC) and Middle Assyrian Empire (1365-1020 BC) the Assyrians ruled over parts of Pre-Iranic northern and western Iran. The Neo-Assyrian Empire (911-605 BC) saw Assyria conquer the Iranic Persians, Medes and Parthians into their empire, together with the ancient pre-Iranic Elamites, Kassites, Manneans and Gutians, and also the Iranic Cimmerians of Asia Minor and Scythians of the Caucasus. The home of the Assyrians in Iran has traditionally been along the western shore of Lake Urmia from the Salmas area to the Urmia plain.
After the fall of Assyria between 612 and 599 BC, after decades of civil war, followed by an attack by an alliance of former subject peoples; the Medes, Persians, Babylonians, Chaldeans, Scythians and Cimmerians, its people became an integral part of the Achaemenid Empire (as did Assyria itself), holding important military, civic and economic positions, and the Achaemenid Persians, having spent centuries under Assyrian domination, were greatly influenced by Assyrian Art and Architecture, modelled their empire upon Assyrian lines, and saw themselves as the successors of the great Assyrian kings. Assyrians are still attested as being extant in the north west of the region during the Parthian Empire (160 BC-223 AD) and Sassanid Empire (224-650 AD), and throughout the Middle Ages, where the Bukhtishu family of physicians were held in great regard by the Persian kings.
There were about 200,000 Assyrians in Iran at the time of the 1976 census. Many emigrated after the revolution in 1979, but at least 50,000 were estimated to be still in Iran in 1987.
In 1900, Assyrians numbered over 76,000 in northwestern Iran, constituting over a quarter of the Azerbaijan province's population and were the largest non-Muslim majority in Urmia. Of the 300 villages around Urmia, 60 were exclusively Assyrians and 60 were mixed villages with Assyrian, Armenian, and Azeri communities. Nevertheless, there were over 115 documented Assyrian villages to the west of Lake Urmia prior to 1918.
During the Assyrian Genocide, which took place in World War I, the Ottoman Army together with allied Kurdish, Azeri and Arab militias along the Iranian-Turkish and Iranian-Iraqi border carried out religiously and ethnically motivated massacres and deportations on unarmed Assyrian civilians (and Armenians) both in the mountains and on the rich plains, resulting in the death of at least 300,000 Assyrians. In 1914 alone, they attacked dozens of villages and drove off all the inhabitants of the district of Gawar. The Assyrians defended themselves and for a time successfully repelled further attacks under the leadership of Agha Petros, seizing control of much of the Urmia region and defeating Ottoman forces and their Kurdish, Arab and Azeri allies in the process. However lack of ammunition and supplies, due mainly to the withdrawal of Russia from the war, and the collapse of allied Armenian forces led to their downfall. Massively outnumbered, surrounded, undersupplied and cut off, the Assyrians suffered terrible massacres.
By the summer of 1918 almost all surviving Assyrians had fled to Tehran or to existing Assyrian communities or refugee camps in Iraq such as Baqubah. Local Kurds, Arabs and Azeris took the opportunity of the last phases of World War I to rob Assyrian homes, murder civilians and leave those remaining destitute. The critical murder that sowed panic in the Assyrian community came when Kurdish militias, under Agha Ismail Simko, assassinated the Patriarch, Mar Benyamin Shimon XIX, on March 3, 1918, under the pretext of inviting him to negotiations, although the Assyrian leader Malik Khoshaba exacted revenge upon Simko by attacking and sacking his citadel, forcing the Kurdish leader to flee for his life.
Most Assyrians in Iran are followers of the Assyrian Church of the East, with a minority of 3,900 following the Chaldean Catholic Church. Some also follow Protestant denominations such as the Assyrian Evangelical Church, Assyrian Pentecostal Church and possibly Russian Orthodoxy due to a Russian Ecclesiastical Mission in Urmia during the 1900s.
Famous Assyrians from Iran