Ch'ŏlsan borders Yŏmju and Tongrim counties to the north, and is bounded on all other sides by water.

Ch'ŏlsan appears as Cheolsan in South Korea's Revised Romanization and as Tieshan in Chinese records, as during its occupation by Mao Wenlong during the Manchu conquest of China.

The terrain is dominated by rolling hills, seldom exceeding 300 m; the highest peak is Yŏndaesan at 393 m. The offshore island of Kado enjoys similar terrain, with Yondaebong reaching 335 m. There are a total of 28 offshore islands, some of which are uninhabited.

Ch'ŏlsan county is divided into 1 ŭp (town), 2 rodongjagu (workers' districts) and 25 ri (villages): Ch'ŏlsan enjoys a relatively mild maritime climate, with the warmest winters in North P'yŏngan.

Local tourist attractions include the Pansong archipelago, known for its scenery, and the Masŏn cavern (마선굴).