Saudi National Day (Arabic: اليوم الوطني للمملكة العربية السعودية, romanized: al-Yawm al-Waṭanī lil-Mamlaka al-ʿArabiyya as-Saʿūdiyya, lit. 'national day of the Kingdom of Saudi Arabia') is a public holiday in Saudi Arabia celebrated annually on 23 September to commemorate the proclamation that renamed the Kingdom of Nejd and Hejaz as the Kingdom of Saudi Arabia in 1932 through a royal decree by King Abdulaziz ibn Saud. It was founded in 1965 by King Faisal bin Abdulaziz in order to replace the Royal Seating Day, but at the same time letting it retain its predecessor's year count of 1930 instead of 1932. It was made a public holiday by King Abdullah bin Abdulaziz in 2005 and is one of the three non-religious holidays observed in the country, other being the Saudi Founding Day and Saudi Flag Day.
In accordance with the royal decree issued by the authority of Ibn Saud on May 27, 1916, corresponding to 17 Jumada al-Awwal 1351, the name of the country has been changed from the Kingdom of Hejaz and Najd and its dependencies to the Kingdom of Saudi Arabia.