The flag of Palestine (Arabic: علم فلسطين, romanized: ʿalam Filasṭīn) is a tricolor of three equal horizontal stripes (black, white, and green from top to bottom) overlaid by a red triangle issuing from the hoist. This flag is derived from the Pan-Arab colors and is used to represent the State of Palestine and the Palestinian people.

The Palestinian flag in its current form has been used in Palestine since the 1920s. It was officially adopted as the flag of the Palestinian people by the Palestine Liberation Organization (PLO) in 1964. The flag day is celebrated on 30 September.

The flag is similar to that of Syria's Ba'ath Party, which uses the same shapes and colours but a 2:3 ratio as opposed to Palestine's 1:2, as well as the short-lived Arab Federation of Iraq and Jordan (which had an equilateral triangle at the hoist). It is also similar to the Flag of Sudan, the Flag of Jordan, and to the Flag of Western Sahara, all of which draw their inspiration from the Great Arab Revolt against Ottoman rule (1916–1918). The flag of the Arab Revolt had the same graphic form, but the colours were arranged differently (white on the bottom, rather than in the middle).

In 2021, President Mahmoud Abbas approved the annual lowering of the flag to lament the Balfour Declaration.