The 1975 Algiers Agreement (commonly known as the Algiers Accord, sometimes as the Algiers Declaration) was an agreement between Iran and Iraq to settle any disputes and conflicts concerning their common border (such as the Shatt al-Arab, known as Arvand Rud in Iran), and it served as basis for the bilateral treaties signed on 13 June and 26 December 1975. The agreement was intended to end disagreement between Iraq and Iran on their borders on the Shatt al-Arab waterway and in Khuzestan, but Iraq also wished to end the Kurdish rebellion. Less than six years after signing the treaty, on 17 September 1980, Iraq abrogated the treaty following a series of border clashes between the two countries and launched a full-scale invasion of Iran on 22 September 1980.

Friction continues on the border despite the treaty being binding under international law and its detailed boundary delimitation remaining in force since it was signed in 1975 and ratified in 1976 by both nations.