Grigory Borisovich Adamov (Russian: ???????? ????????? ??????; born Abram Borukhovich Gibs; ????? ????????? ????; May 18, 1886, Kherson, then Russian Empire, now Ukraine, - June 14, 1945, Moscow, USSR) was a Soviet science fiction writer, best known for his novels Conquerors of the Underground (1937), The Mystery of the Two Oceans (1939) and The Ousting of the Ruler (1946).