Gardiner is a city in Kennebec County, Maine, United States. The population was 5,961 at the 2020 census. Popular with tourists, Gardiner is noted for its culture and old architecture. Gardiner is a nationally accredited Main Street America community. It is included in the Augusta, Maine micropolitan New England City and Town Area.

The Kennebec River is a 170-mile-long (270 km) river within the U.S. state of Maine. It rises in Moosehead Lake in west-central Maine. The East and West Outlets join at Indian Pond and the river flows southward. Harris Station Dam, the largest hydroelectric dam in the state, was constructed near that confluence. The river is joined at The Forks by its tributary the Dead River, also called the West Branch.