Necmettin Sadık Sadak (1890, Isparta – 1953, New York) was a Turkish politician, former minister of Foreign Affairs of Turkey and former chairman of the Turkish sports club Galatasaray.
He was born in Isparta, Ottoman Empire in 1890. After graduating from Galatasaray High School in 1910, he studied Humanities in the University of Lyon, France until 1914. After his return to Turkey, he started to work in fields of sociology. In 1928 he was elected as member of national parliament from Sivas province . His political success continued and he was elected again for five consecutive times to parliament. He represented Turkey many times in international conferences. Between 1947 and 1950, he was the Minister of Foreign Affairs of Turkey. Sadak also elected as the chairman of Galatasaray in 1928. Although there was no national football league established in Turkey in 1920's, Galatasaray won an Istanbul League title, while Sadak was the president. He died in 21 September 1953.
| Preceded by Hasan Saka |
Minister of Foreign Affairs of Turkey 1947–1950 |
Succeeded by Fuat Köprülü |
| Preceded by İbrahim Piroğlu |
President of Galatasaray S.K. 1928–1929 |
Succeeded by Tahir Kevkep |