Jerusalem is the capital of Israel and its largest city in both population and area, with a population of 747,600 residents over an area of 125.1 square kilometres (48.3 sq mi) if disputed East Jerusalem is included. Located in the Judean Mountains, between the Mediterranean Sea and the northern tip of the Dead Sea, modern Jerusalem has grown up outside the Old City.

The city has a history that goes back to the 4th millennium BCE, making it one of the oldest cities in the world. Jerusalem has been the holiest city in Judaism and the spiritual center of the Jewish people since the 10th century BCE, contains a number of significant ancient Christian sites, and is considered the third-holiest city in Islam. Despite having an area of only 0.9 square kilometer (0.35 square mile),the Old City is home to sites of key religious importance, among them the Temple Mount, the Western Wall, the Church of the Holy Sepulchre, the Dome of the Rock and al-Aqsa Mosque. The old walled city, a World Heritage site, has been traditionally divided into four quarters, although the names used today — the Armenian, Christian, Jewish, and Muslim Quarters — were introduced in the early 19th century. The Old City was nominated for inclusion on the List of World Heritage Sites in danger by Jordan in 1982. In the course of its history, Jerusalem has been destroyed twice, besieged 23 times, attacked 52 times, and captured and recaptured 44 times.

Today, the status of Jerusalem remains one of the core issues in the Israeli-Palestinian conflict. Israel's annexation of East Jerusalem has been repeatedly condemned by the United Nations and related bodies, and Arab Palestinians foresee East Jerusalem as the capital of their future state. In the wake of United Nations Security Council Resolution 478 (passed in 1980), most foreign embassies moved out of Jerusalem, although some countries, such as the United States, still own land in the city and pledge to return their embassies once political agreements warrant the move.

Jerusalem plays an important role in Judaism, Christianity, and Islam. The 2000 Statistical Yearbook of Jerusalem lists 1204 synagogues, 158 churches, and 73 mosques within the city. Despite efforts to maintain peaceful religious coexistence, some sites, such as the Temple Mount, have been a continuous source of friction and controversy.

Jerusalem has been sacred to the Jews since King David proclaimed it his capital in the 10th century BCE. Jerusalem was the site of Solomon's Temple and the Second Temple. It is mentioned in the Bible 632 times. Today, the Western Wall, a remnant of the wall surrounding the Second Temple, is a Jewish holy site second only to the Holy of Holies on the Temple Mount itself. Synagogues around the world are traditionally built with the Holy Ark facing Jerusalem, and Arks within Jerusalem face the "Holy of Holies". As prescribed in the Mishna and codified in the Shulchan Aruch, daily prayers are recited while facing towards Jerusalem and the Temple Mount. Many Jews have "Mizrach" plaques hung on a wall of their homes to indicate the direction of prayer.
Christianity reveres Jerusalem not only for its Old Testament history but also for its significance in the life of Jesus. According to the New Testament, Jesus was brought to Jerusalem soon after his birth and later in his life cleansed the Second Temple. The Cenacle, believed to be the site of Jesus' Last Supper, is located on Mount Zion in the same building that houses the Tomb of King David. Another prominent Christian site in Jerusalem is Golgotha, the site of the crucifixion. The Gospel of John describes it as being located outside Jerusalem, but recent archaeological evidence suggests Golgotha is a short distance from the Old City walls, within the present-day confines of the city. The land currently occupied by the Church of the Holy Sepulchre is considered one of the top candidates for Golgotha and thus has been a Christian pilgrimage site for the past two thousand years.

Jerusalem is considered the third-holiest city in Islam. For approximately a year, before it was permanently switched to the Kabaa in Mecca, the qibla (direction of prayer) for Muslims was Jerusalem. The city's lasting place in Islam, however, is primarily due to Muhammad's Night of Ascension (c. 620 CE). Muslims believe Muhammad was miraculously transported one night from Mecca to the Temple Mount in Jerusalem, whereupon he ascended to Heaven to meet previous prophets of Islam. The first verse in the Qur'an's Surat al-Isra notes the destination of Muhammad's journey as al-Aqsa (the farthest) mosque, in reference to the location in Jerusalem. Today, the Temple Mount is topped by two Islamic landmarks intended to commemorate the event — al-Aqsa Mosque, derived from the name mentioned in the Qur'an, and the Dome of the Rock, which stands over the Foundation Stone, from which Muslims believe Muhammad ascended to Heaven.