Alexandr Vladimirovich Ryazanov (; 6 September 1932 â 18 January 2026) was a Soviet air defense designer. He designed the S-25, S-75, S-200, and S-300 air defense systems. He was a recipient of the USSR State Prize, and the Order of the Badge of Honour.
Ryazanov died on 18 January 2026, at the age of 93.