The Saudi-Iraqi neutral zone was an area on the border between Saudi Arabia and Iraq, established by a treaty negotiated in the 1920s defining the borders between them. Within the neutral zone, the border between the two countries had not been settled. Tentative agreement on the partition of the Saudi-Iraqi neutral zone was reached in 1981, and partition was finalized by 1983.

The Saudi-Iraqi neutral zone formerly had the ISO 3166-1 codes NT and NTZ. Thess codes were discontinued in 1993. There was also a similar Saudi-Kuwati neutral zone; however this zone was never assigned an ISO 3166 code, since it was partitoned in 1971, and ISO 3166 was not adopted until 1974.