Taeanhaean National Park, Marine national park in South Chungcheong, South Korea.

Taeanhaean National Park is South Korea's only coastal national park, stretching along the Taean Peninsula in South Chungcheong Province from Garorim Bay to Anmyeon Island. It protects a ria coastline of drowned valleys, tidal flats, sand dunes and rocky shores, with beaches such as Mallipo, Kkotji and Monganpo and about 72 islands offshore.

Taeanhaean National Park was designated on 20 October 1978 as Seosan Coastal National Park, South Korea's thirteenth national park. On 22 March 1990 its name was changed to Taeanhaean National Park. The park area has been adjusted several times and now covers 377.019 km², about 5.7% of the country's total national park area.

The park's name comes from Taean County, and it is South Korea's only coastal-type national park. Nearby cultural properties include the birthplace of independence activist Okpa Lee Jong-il, the Taean Rock-carved Buddha Triad, the three-story stone pagoda at Heungjusa Temple, Baekhwasanseong Fortress, Anheungseong Fortress and the seated Sakyamuni Buddha of Mongsan-ri.

The park features multiple camping areas and marked walking trails that explore different sections. Checking current conditions before visiting is wise, as the coastal location means weather can change quickly.

Taeanhaean is South Korea's only coastal-type national park, and its 76 islands inside the park are mostly uninhabited; only Janggo, Godae, Oedo and Gaui have residents. Nan Island's vertical cliffs keep predators out, making it a breeding site for black-tailed gulls.