Ch'ŏngmasansŏng () was a Korean fortress of Baekje in what is now Buyeo County, South Chungcheong Province, South Korea. On January 21, 1963, it was designated Historic Site of South Korea No. 34.
It is located on the mountain Wolmyeongsan. It was constructed in the late Baekje period, and used to defend the capital Sabi. It was the largest and finest of Baekje's fortresses. It had a circumference of . A number of former sites of its facilities are known, including 10 gates, 36 guard posts, 17 wells, and 14 tombs.