The land that became Jordan forms part of the history-rich Fertile Crescent region. Its known history began around 2000 B.C., when Semitic Amorites settled around the Jordan River in the area called Canaan. Subsequent invaders and settlers included Hittites, Egyptians, Israelites, Assyrians, Babylonians, Persians, Greeks, Romans, Byzantines, Arab Muslims, Christian Crusaders, Mameluks, Ottoman Turks, and, finally, the British. At the end of World War I, the territory now comprising Israel, Jordan, the West Bank, the Gaza Strip, and Jerusalem was awarded to the United Kingdom by the League of Nations as the mandate for Palestine. In 1922, in an attempt to assuage Arab anger resulting from the Balfour Declaration, with the approval of the League of Nations, the British created the semi-autonomous Arab Emirate of Transjordan in all Palestinian territory east of the Jordan river. The British installed the Hashemite Prince Abdullah, while continuing the administration of Palestine and Transjordan under a single British High Commissioner. The mandate over Transjordan ended on 22 May 1946; on 25 May, the country became the independent Hashemite Kingdom of Transjordan. It ended its special defense treaty relationship with the United Kingdom in 1957.

Transjordan opposed the creation of Israel in May 1948, and took part in the warfare between the Arab states and the newly founded State of Israel. The armistice agreements of 3 April 1949 left Jordan in control of the West Bank and provided that the armistice demarcation lines were without prejudice to future territorial settlements or boundary lines.

In 1950, Transjordan annexed the West Bank, and the country was renamed "the Hashemite Kingdom of Jordan" to reflect this. The annexation was recognized only by the United Kingdom.

Jordan signed a mutual defense pact in May 1967 with Egypt, and it participated in the June 1967 war against Israel along with Syria, Egypt, and Iraq. During the war, Jordan lost its control of the West Bank and all of Jerusalem. In 1988, Jordan renounced all claims to the West Bank but retained an administrative role pending a final settlement, and its 1994 treaty with Israel allowed for a continuing Jordanian role in Muslim and Christian holy places in Jerusalem. The international community as represented in the United Nations considers the West Bank to be territory occupied by Israel and believes that its final status should be determined through direct negotiations among the parties concerned on the basis of UN Security Council Resolutions 242 and 338.

The 1967 war led to a dramatic increase in the number of Palestinians, especially from the West Bank, living in Jordan. Its Palestinian refugee population – 700,000 in 1966 – grew by another 300,000 from the West Bank. The period following the 1967 war saw an upsurge in the power and importance of Palestinian resistance elements (fedayeen) in Jordan. The heavily armed fedayeen constituted a growing threat to the sovereignty and security of the Hashemite state, and open fighting erupted in June 1970. The battle in which Palestinian fighters from various Palestinian Liberation Organization (PLO) groups were expelled from Jordan is commonly known as Black September.

Other Arab governments attempted to work out a peaceful solution, but by September, continuing fedayeen actions in Jordan – including the destruction of three international airliners hijacked by the Popular Front for the Liberation of Palestine and held in the desert east of Amman – prompted the government to take action to regain control over its territory and population. In the ensuing heavy fighting, a Syrian tank force took up positions in northern Jordan to support the fedayeen but subsequently retreated. By 22 September, Arab foreign ministers meeting at Cairo had arranged a cease-fire beginning the following day. Sporadic violence continued, however, until Jordanian forces led by Habis Al-Majali won a decisive victory over the fedayeen in July 1971, expelling them from the country.

At the Rabat summit conference in 1974, Jordan agreed, along with the rest of the Arab League, that the PLO was the "sole legitimate representative of the Palestinian people", thereby relinquishing to that organization its role as representative of the West Bank Palestinians.

No fighting occurred along the 1967 Jordan River cease-fire line during the October 1973 Arab-Israeli war, but Jordan sent a brigade to Syria to fight Israeli units on Syrian territory. Jordan did not participate in the Gulf War of 1990-91. In 1991, Jordan agreed, along with Syria, Lebanon, and Palestinian representatives, to participate in direct peace negotiations with Israel sponsored by the U.S. and Russia. It negotiated an end to hostilities with Israel and signed a declaration to that effect on July 25, 1994 (see Washington Declaration). As a result, an Israeli-Jordanian peace treaty was concluded on October 26, 1994. Following the outbreak of Israeli-Palestinian fighting in September 2000, the Jordanian government offered its good offices to both parties. Jordan has since sought to remain at peace with all of its neighbors.