Count Ōgimachi Sanemasa (Japanese: 正親町実正; 20 July 1855 – 26 June 1923) was a Japanese courtier and pharmacist who served as Grand Chamberlain to the Emperor from 1919 to 1922.
Born to a prestigious kuge family, his father was an imperial counsellor and his aunt the biological mother of Emperor Kōmei. He was the governor of Saitama Prefecture (1899–1900). He was a recipient of the Order of the Sacred Treasure. He was made a count in 1884, a recipient of the Order of the Rising Sun, 4th class in 1906, a recipient of the Order of the Sacred Treasure in 1910 and a recipient of the World War I Victory Medal in 1915.