Manisan (Korean: 마니산) is a mountain in Incheon, South Korea. It is situated in Ganghwa County and is the highest peak on Ganghwa Island. Manisan has an elevation of 469.4 m (1,540 ft). There is a popular hiking trail to the summit; at the summit is Chamseongsdan, an altar where Dangun (the founding father of Korea) performed ritual ceremonies.

• List of mountains in Korea

• An Gyeong-ho (2003). 신 한국 100 명산 ('The New' 100 Korean Mountains). Seoul: 깊은솔 (Gipeunsol). ISBN 978-89-89917-07-6.