Sultanate of Nejd

{{Infobox country

| native_name = {{native_name|ar|سلطنة نجد}}
{{Transliteration|ar|Salṭanat Najd}}

| conventional_long_name = Sultanate of Nejd

| common_name = Nejd

| status =

| status_text =

| p1 = Emirate of Nejd and Hasa

| flag_p1 = Flag of the Emirate of Nejd and Hasa.svg

| p2 = Emirate of Jabal Shammar

| flag_p2 = Flag of the Emirate of Ha'il.svg

| p3 = Sheikdom of Upper Asir

| flag_p3 = Flag of Upper Asir.svg

| s1 = Kingdom of Hejaz and Nejd{{!}}Kingdom of Hejaz and Sultanate of Nejd

| flag_s1 = Flag of the Kingdom of Hejaz and Nejd.svg

| image_flag = Flag of the Sultanate of Nejd.svg

| flag_type = {{FIAV|sinister}} Flag of Nejd

| image_coat =

| coa_size = 110px

| image_map = Sultanate of Nejd 1921.svg

| image_map_caption = Sultanate of Nejd

| capital = Riyadh

| common_languages = Arabic

| religion = Sunni Islam

| demonym = Nejdi

| government_type = Islamic absolute monarchy

| title_leader = Sultan

| leader1 = Ibn Saud

| year_leader1 = 1921–1926

| title_representative = Viceroy

| representative1 = Faisal {{small|(Arar)}}

| year_representative1 = 1921–26

| representative2 = Saud {{small|(Najd)}}

| year_representative2 = 1921–26

| representative3 = Nasser {{small|(Ahsa)}}

| year_representative3 = 1921–26

| era = Interwar period

| date_start = 2 November

| year_start = 1921

| event_end = Hejaz annexed

| date_end = 8 January

| year_end = 1926

| legislature = None (rule by decree) (until 1924)
National Council (1924–1926)

| footnotes =

|today={{flagicon|Saudi Arabia}} Saudi Arabia}}

The Sultanate of Nejd ({{langx|ar|سلطنة نجد}}, {{Transliteration|ar|Salṭanat Najd}}) was the third iteration of the Third Saudi State, from 1921 to 1926. It was a monarchy led by the House of Saud, and a legal predecessor of modern-day Saudi Arabia. This version of the Third Saudi State was created when Abdul Aziz ibn Saud, Emir of Riyadh, declared himself sultan over Nejd and its dependencies.Madawi Al Rasheed. (2002). A History of Saudi Arabia. Cambridge, England, UK: Cambridge University Press, p. 63. On the 2 December 1922, the Nejd signed an agreement with Kuwait defining their border with each other. The border would be a straight line along the 29th parallel.{{cite web|title=No. 1083 SULTANATE OF NEJD and KUWAIT|date=1922|url=https://treaties.un.org/doc/Publication/UNTS/Volume%201750/II-183.pdf}} In December 1925, the Kingdom of Hejaz surrendered to the forces of Abdul Aziz ibn Saud, who was thereafter proclaimed king of Hejaz in January 1926 and merged his dominions into the Kingdom of Hejaz and Nejd.