Iraqis (Arabic: العراقيون al-ʿIrāqiyyūn; Kurdish: عێراقییەکان, romanized: 'Êraqiyekan) are the citizens and nationals of the Republic of Iraq. The majority of Iraqis are Arabs, with Kurds accounting for the largest ethnic minority, followed by Turkmen. Other ethnic groups from the country include Yazidis, Assyrians, Mandaeans, and other Mesopotamian Minorities. Approximately 95% of Iraqis adhere to Islam, with nearly 64% of this figure consisting of Shia Muslims and the remainder consisting of Sunni Muslims. The largest minority religion is Christianity at 1%, while other religions collectively represent as much as 4% of the Iraqi populace.

The territory of modern-day Iraq largely overlaps with what was historically known as Mesopotamia, which was home to many noteworthy civilizations, such as Sumer, Akkad, Assyria, and Babylonia. The fall of these native Mesopotamian civilizations, particularly Babylon in the 6th century BC, marked the beginning of centuries-long foreign conquests and rule. Recent studies indicate that the various Iraqi ethnic groups have significant genetic similarities, likely due to the long history of intermingling and assimilation between foreign and indigenous populations in the region.

Arabic and Kurdish are Iraq's two official languages; Mesopotamian Arabic is the Iraqi Arabic variety, having emerged in the aftermath of the Arab conquest of Mesopotamia in the 7th century. The process of Arabization and Islamization that began during the medieval era resulted in the decline of various Eastern Aramaic languages and local religions, most notably during the Abbasid Caliphate, when the city of Baghdad became the capital of the Muslim world and the centre of the Islamic Golden Age. Mesopotamian Arabic is considered to be the most Aramaic-influenced dialect of Arabic, as Aramaic originated in Mesopotamia and spread throughout the Fertile Crescent during the Neo-Assyrian period, eventually becoming the lingua franca of the entire region prior to the early Muslim conquests. Other languages spoken within the Iraqi community include Turkmen Turkic, Neo-Aramaic, and Mandaic.

In ancient and medieval times Mesopotamia was the political and cultural centre of many great empires and civilizations, such as the Akkadian Empire, Assyria, Assyrian Empire and Babylonian Empire. The ancient Mesopotamian civilization of Sumer is the oldest known civilization in the world, and thus Iraq is widely known as the Cradle Of Civilization. Iraq remained an important centre of civilization for millennia, up until the Muslim conquest of Mesopotamia and subsequently Abbasid Caliphate (of which Baghdad was the capital), which was the most advanced empire of the medieval world (see Islamic Golden Age). Hence, Mesopotamia has witnessed many periods of emigration and immigration in the past.

Further information on Iraq's civilization and cultural history can be found in the following chronology of Iraqi history:

One study found that Haplogroup J-M172 originated in northern Iraq. In spite of the importance of this region, genetic studies on the Iraqi people are limited and generally restricted to analysis of classical markers due to Iraq's modern political instability, although there have been several published studies displaying a genealogical connection between all Iraqi peoples and the neighboring countries, across religious, ethnic and linguistic barriers. Studies indicate that the different ethno-religious groups of Iraq (Mesopotamia) share significant similarities in genetics and that Mesopotamian Arabs, who make up the majority of Iraqis, Genetic analysis indicates that Iraqi Arabs have the smallest genetic distance to Iraqi Kurds, and show similarly close affinities to Yemenis and Kuwaitis.

No significant differences in Y-DNA variation were observed among Iraqi Mesopotamian Arabs, Assyrians, or Kurds. Modern genetic studies indicate that Iraqi Arabs and Iraqi Kurds are distantly related, though Iraqi Mesopotamian Arabs are more related to Iraqi-Assyrians than they are to Iraqi Kurds.

For both mtDNA and Y-DNA variation, the large majority of the haplogroups observed in the Iraqi population (H, J, T, and U for the mtDNA, J-M172 and J-M267 for the Y-DNA) are those considered to have originated in Western Asia and to have later spread mainly in West Asia. The Eurasian haplogroups R1b and R1a represent the second most frequent component of the Iraqi Y-chromosome gene pool, the latter suggests that the population movements from Central Asia into modern Iran also influenced Iraq.