The State of Qatar, located on a peninsula which juts north into the Persian, or Arabian, Gulf, shares its only land boundary with the Kingdom of Saudi Arabia, the largest country in the Arabian Peninsula. Qatar and Saudi Arabia’s 54 mile (86 kilometer) land boundary follows a large, u-shaped curve, originating at the Dawhat Salwá in the west and ending at the mouth of the Khor Al-Adaid (Inland Sea) in the east. The territorial division between the two States can be traced back to 1913 when the precursor to the Kingdom of Saudi Arabia conquered Ottoman territory in the neighboring Qatar Peninsula.

A precise boundary was first delimited between the two States by a 1965 Agreement. In 1999, seven years after the establishment of a Joint Technical Commission, the land boundary was adjusted and demarcated. Modified in 2001 and again in 2008, the land boundary now encloses the entirety of the Khor Al Adaid within Qatar in return for Saudi Arabian maritime access into the Persian/Arabian Gulf.

Qatar and Saudi Arabia also have an established maritime boundary.