The Fourth River is an American literary magazine with a focus on nature and place-based writing.

Publication is annual as a quality paperback and twice monthly in its online format.

The fourth river, unseen yet indispensable to the city's riverine ecosystem, is actually an aquifer geologists call the "Wisconsin Glacial Flow".

Founding editor and poet Jeffrey Thomson wrote in first issue that the genesis of The Fourth River is the idea that “between and beneath the visible framework of the human world and the built environment, there exist deeper currents of force and meaning supporting the very structure of that world".

The journal also takes inspiration from Rachel Carson, the biologist, zoologist, and nature writer who is one of Chatham's most notable alumnae.