An inland waterway is a navigable water route through a land mass, consisting of narrow channels such as canals, rivers, lakes, estuaries, intracoastal waterways, portages, and other corridors, often in combination.

The route can combine natural water bodies with constructed channels or overland transfer sections. Continuous water along every part is not required.

The stated scope includes estuaries and intracoastal waterways. Oceanic shipping routes instead cross open ocean-connected water without penetrating the landmass in that way.