Ōishi Sadahisa
RETAINER OF THE OGIGAYATSU-UESUGI BRANCH OF THE UESUGI, AND THE BUILDER OF TAKIYAMA CASTLE
Oishi Sadahisa; Sadahisa; Sadahisa Ōishi
Ōishi Sadahisa (大石 定久; 1 May 1491 – 27 October 1549) was a retainer of the Ogigayatsu-Uesugi branch of the Uesugi, and the builder of Takiyama Castle (滝山城). After the Uesugi were defeated at Kawagoe in 1545, Ōishi accepted the authority of the Hōjō.