Egyptian diplomat who, as secretary-general of the Arab League (1972–79), was unable to prevent Egypt's 1979 expulsion from the league after that country signed a peace treaty with Israel.

Riyāḍ studied at the Egyptian military academy and later received a doctorate in engineering. After serving in the Egyptian army during the first Arab-Israeli war (Arab-Israeli wars) (1948–49), he was a member of the mixed armistice committee. Following the 1952 coup that deposed King Fārūq I (Farouk I), Riyāḍ joined the foreign ministry, where he served as head of the Palestine desk (1952–53), director of Arab affairs (1953–55), ambassador to Syria (1955–58), special adviser to President Gamal Abdel Nasser (Nasser, Gamal Abdel) (1958–62), and permanent ambassador to the United Nations (1962–64). As Egyptian foreign minister (1964–72) and deputy premier (1971–72), he urged a peaceful settlement of the Arab-Israeli conflict but also persuaded many nations to join in an international boycott of Israel to force concessions. In 1972 he was named to succeed ʿAbd al-Khāliq Hassūnah (Ḥassūnah, ʿAbd al-Khāliq) as secretary-general of the Arab League. Although he disagreed with President Anwar el-Sādāt (Sādāt, Anwar el-)'s peace negotiations, Riad struggled to hold the league together. In 1979, after the other Arab states voted to expel Egypt from the league and move its headquarters from Cairo to Tunis, Tunisia, Riyāḍ resigned from public office but remained a respected government adviser.