Sa'ad bin Abdul Rahman Al Saud (Arabic: سعد بن عبد الرحمن آل سعود;1890–1915) was the brother of Abdulaziz, Emir of Nejd (who later founded the Kingdom of Saudi Arabia).

[1] He was the youngest son of the reigning Emir of Nejd, Abdul Rahman bin Faisal, from his marriage to Sara bint Ahmed Al Sudairi.

[4] He also had a number of half-siblings from his father's other marriages,[5] including Muhammad, Abdullah, Ahmed, and Musaid, who all had roles in the Saudi government.

[8] Sa'ad was brought to Sharif Hussein[8] who sent his envoy Khalid ibn Luai, Amir of Al Khurmah, to Emir Abdulaziz demanding that he should accept the sovereignty of the Ottoman government in the region as well as pay an annual sum of money to the Ottoman government for Sa'ad's release.

Sara's half-sister Al Anoud married two sons of Sa'ad bin Abdul Rahman.

[17] Sa'ad's grandson, Bandar bin Saud, a former air force pilot, was among the victims in the Swissair Flight 111 accident on his way from New York City to Geneva on 2 September 1998.