The Kingdom of Hejaz and Nejd (Arabic: مملكة الحجاز ونجد, Mamlakat al-Ḥijāz wa-Najd), initially the Kingdom of Hejaz and Sultanate of Nejd (Arabic: مملكة الحجاز وسلطنة نجد, Mamlakat al-Ḥijāz wa-Salṭanat Najd), was a dual monarchy ruled by Abdulaziz following the victory of the Saudi Sultanate of Nejd over the Hashemite Kingdom of the Hejaz in 1925.

On 8 January 1926, Abdulaziz, the Sultan of Nejd, was crowned King of the Hejaz in the Masjid al-Haram in Makkah, and he elevated Nejd to the status of a kingdom on 29 January 1927.

[1] At the Treaty of Jeddah on 20 May 1927, Abdulaziz's realm was recognised by the United Kingdom of Great Britain and Northern Ireland, and was addressed as the Kingdom of Hejaz and Nejd.

For the next five years, Abdulaziz administered the two parts of his dual kingdom as separate units.

In 1926, the Kingdom of Hejaz and Nejd was recognised by the Union of Soviet Socialist Republics, followed by the United States of America in 1931.