Qaboos bin Said Al Said (Arabic: قابوس بن سعيد آل سعيد, IPA: [qaː.buːs bin sa.ʕiːd ʔaːl sa.ʕiːd]; 18 November 1940 – 10 January 2020) was the Sultan of Oman from 23 July 1970 until his death in 2020. A fifteenth-generation descendant of the founder of the House of Al Said, he was the longest-serving leader in the Middle East and Arab world at the time of his death.The only son of Sultan Said bin Taimur of Muscat and Oman, Qaboos was educated in Suffolk, England. After graduating from the Royal Military Academy Sandhurst, he served briefly in the British Army. He returned to Oman in 1966 and was the subject of considerable restrictions from his father. In 1970, Qaboos ascended to the Omani throne after overthrowing his father in a coup d'état, with British support. The country was subsequently renamed the Sultanate of Oman.

As Sultan, Qaboos implemented a policy of modernization and ended Oman's international isolation. His reign saw a rise in living standards and development in the country, the abolition of slavery, the end of the Dhofar Rebellion, and the promulgation of Oman's constitution. Suffering from poor health in later life, Qaboos died in 2020. He had no children, so he entailed the royal court to reach consensus on a successor upon his death. As a precaution he hid a letter which names the successor in case an agreement is not achieved. After his death the royal court decided to view Qaboos's letter and named his intended successor, his cousin Haitham bin Tariq, as Sultan.