This article is devoted to the life and scientific activity of a prominent scientist, geologist, and public figure - Okitai (Sergey) Alikhanovich Bukeykhanov (1910–1957), who made a significant contribution to the development of geological science in Kazakhstan in the mid-20th century. He was the son of the national leader, statesman, member of the Russian State Duma, and head of the Alash movement, Alikhan Nurmukhamedovich Bukeykhan. Due to his father’s political activities and the repressions against his relatives, information about Okitai’s life and works remained inaccessible for a long time. The authors introduce archival materials and rare documents into scientific circulation, analyzing his life path, his contribution to geological exploration in the Zhezkazgan and Karsakpay regions, and his scientific collaboration with prominent scholars such as Kanysh Imantayevich Satpayev. In addition, based on media sources and historical data, the article provides a comprehensive analysis of Okitai Bukeykhanov’s immense contribution to the development of Kazakhstan’s mining industry and geological science.