Hasan Abdullayev (also spelled as Gasan Mamed Bagir ogly Abdullaev; Azerbaijani: Həsən Məmmədbağır oğlu Abdullayev; Russian: Гасан Мамед Багир оглы Абдуллаев; August 20, 1918 – September 1, 1993) was a leading Soviet and Azerbaijani physicist, scientist and public official, who served as President of the National Academy of Sciences of the Azerbaijan SSR. He was a Doctor of Sciences in physics and mathematics, Professor of physics and mathematics, Director of the Institute of Mathematics and Physics of the National Academy of Sciences of the Azerbaijan SSR, full Academician of the National Academy of Sciences of the Azerbaijan SSR, corresponding member of the Soviet Academy of Sciences and Russian Academy of Sciences, and in 1970-1983 was the longest-serving President of the National Academy of Sciences of the Azerbaijan SSR. He was also an elected member of the Azerbaijan SSR Parliament, and the elected member of the 8th, 9th and 10th convocations of the Supreme Soviet of the Soviet Union. Academician Abdullayev was one of the founders of the Soviet semiconductors physics and a leading scientist in new technologies. He made an outstanding contribution to the development of electronics, astrophysics, aeronautics, medicine, biophysics and defense industries. Academician Abdullayev was the author of 585 Soviet and foreign patents, including 171 secret and 65 top secret patents, author of 28 scientific books (monographs), over 800 journal and encyclopedia articles in English, Russian and Azerbaijani languages.