Baghdad is the capital and largest city of Iraq. Situated on the Tigris, it is part of the Baghdad Governorate and is located near the Diyala River. With a population variously estimated at 6 or over 7 million, Baghdad forms 22% of Iraq's total population. In comparison to its large population, the city has a small area at just 673 square kilometers (260 sq mi). It is the second-largest city in the Arab world after Cairo, and the second-largest city in West Asia after Tehran. Baghdad is historically known as a global cultural hub.

In 762 AD, Baghdad was founded as the capital of the Abbasid Caliphate, and became its most notable major development project. Within a short time, it evolved into a significant cultural and intellectual center of the Muslim world. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as a multi-ethnic and multi-religious environment, garnered it a worldwide reputation as the "Center of Learning". For much of the Abbasid era, during the Islamic Golden Age, Baghdad was the largest city in the world. Its population peaked at more than one million people. The city was largely destroyed at the hands of the Mongol Empire in 1258, resulting in a decline that would linger through many centuries due to frequent plagues and multiple successive empires, such as the Mesopotamian Mamluk Sultanate and the Ottoman Empire, until the World War I.

The city served as capital of the former British Mandate of Mesopotamia. With the recognition of Iraq as an independent monarchical state in 1932, Baghdad gradually regained some of its former prominence as a significant center of Arab culture. Baghdad has faced severe infrastructural damage due to the Iraq War, which began with the United States-led invasion of Iraq, the subsequent insurgency and renewed war, resulting in a substantial loss of cultural heritage and historical artifacts. During this period, it had one of the highest rates of terrorist attacks in the world. However, terrorist attacks have gradually been on the decline since the territorial defeat of the Islamic State militant group in Iraq in 2017, and are very rare now.

A major center of Islamic history, the city is known for its numerous historic mosques. It includes museums such as the Iraq Museum, Baghdadi Museum and Abd al-Karim Qasim Museum. Baghdad is also nicknamed as "City of Palaces", as its home to numerous palaces such as Abbasid Palace, Radwaniyah Palace and Al-Faw Palace. Previously being multi-religious city, the city is also many churches, mandis and synagogues. Through its airport, Baghdad is known as the "Gateway of Iraq".