The Kfar Etzion massacre refers to a massacre of Jews that took place after a two-day battle in which Jewish Kibbutz residents and Haganah militia defended Kfar Etzion from a combined force of the Arab Legion and local Arab men on May 13, 1948, the day before the Israeli Declaration of Independence.

Of the 129 Haganah fighters and Jewish kibbutzniks who died during the defence of the settlement, Martin Gilbert states that fifteen were killed on surrendering.Controversy surrounds the responsibility and role of the Arab Legion in the killing of those who surrendered. The official Israeli version maintains that the kibbutz residents and Haganah soldiers were massacred by local Arabs and the Arab Legion of the Jordanian Army as they were surrendering. The Arab Legion version maintains that the Legion arrived too late to prevent the kibbutz attack by men from nearby Arab villages, which was allegedly motivated by a desire to avenge the massacre of Deir Yassin and the destruction of one of their villages several months earlier. The surrendering Jewish residents and fighters are said to have been assembled in a courtyard, only to be suddenly fired upon; it is said that many died on the spot, while most of those who managed to flee were hunted down and killed.Four prisoners survived the massacre and were transferred to Transjordan. Immediately following the surrender on May 13, the kibbutz was looted and razed to the ground. The members of the three other kibbutzim of the Gush Etzion surrendered the next day and were taken as POWs to Jordan.

The bodies of the victims were left unburied until, one and a half years later, the Jordanian government allowed Shlomo Goren to collect the remains, which were then interred at Mount Herzl. The survivors of the Etzion Bloc were housed in former Arab houses in Jaffa.

The 1948 (or First) Arab–Israeli War was the second and final stage of the 1947–1949 Palestine war. It formally began following the end of the British Mandate for Palestine at midnight on 14 May 1948; the Israeli Declaration of Independence had been issued earlier that day, and a military coalition of Arab states entered the territory of British Palestine in the morning of 15 May.

The first deaths of the 1947–1949 Palestine war occurred on 30 November 1947 during an ambush of two buses carrying Jews. There had been tension and conflict between the Arabs and the Jews, and between each of them and the British forces since the 1917 Balfour Declaration and the 1920 creation of the British Mandate of Palestine. British policies dissatisfied both Arabs and Jews. Arab opposition developed into the 1936–1939 Arab revolt in Palestine, while the Jewish opposition developed into the 1944–1947 Jewish insurgency in Palestine. In 1947, these ongoing tensions erupted into civil war following the 29 November 1947 adoption of the United Nations Partition Plan for Palestine, which planned to divide Palestine into an Arab state, a Jewish state, and the Special International Regime encompassing the cities of Jerusalem and Bethlehem.

On 15 May 1948, the civil war transformed into a conflict between Israel and the Arab states following the Israeli Declaration of Independence the previous day. Egypt, Transjordan, Syria, and expeditionary forces from Iraq entered Palestine. The invading forces took control of the Arab areas and immediately attacked Israeli forces and several Jewish settlements. The 10 months of fighting took place mostly on the territory of the British Mandate and in the Sinai Peninsula and southern Lebanon, interrupted by several truce periods.As a result of the war, the State of Israel controlled the area that the UN had proposed for the Jewish state, as well as almost 60% of the area proposed for the Arab state, including the Jaffa, Lydda, and Ramle area, Galilee, some parts of the Negev, a wide strip along the Tel Aviv–Jerusalem road, and some territories in the West Bank. Israel also took control of West Jerusalem, which was meant to be part of an international zone for Jerusalem and its environs. Transjordan took control of East Jerusalem and the remainder of the former British mandate, annexing it the following year, and the Egyptian military took control of the Gaza Strip. At the Jericho Conference on 1 December 1948, 2,000 Palestinian delegates called for unification of Palestine and Transjordan as a step toward full Arab unity. The conflict triggered significant demographic change throughout the Middle East. Around 700,000 Palestinian Arabs fled or were expelled from their homes in the area that became Israel, and they became Palestinian refugees in what they refer to as the Nakba ("the catastrophe"). In the three years following the war, about 700,000 Jews emigrated to Israel. Around 260,000 Jews moved to Israel from the Arab world during and immediately after the war.