thumb|300x300px|Montrose Basin, [[Angus, Scotland|Angus, Scotland]]
Montrose Basin is a nearly circular tidal basin which makes up part of the estuary of the River South Esk and which sits just inland of the town of Montrose in Angus on the east coast of Scotland. The basin is protected by a number of designations; it is managed by the Scottish Wildlife Trust as a Wildlife Reserve, as well as being designated as a Local Nature Reserve, Site of Special Scientific Interest, and a Ramsar Site.
The Basin has been exploited for its seafood, especially the Atlantic salmon but commercial fisheries for this species ended in 2018; and mussel cultivation gave it the largest mussel beds in the country during the 19th and early 20th centuries.
The Montrose Basin was hit by a tsunami in 6,100 BCE, generated by the massive underwater Storegga Slide, in Norway. It was high when it hit the basin, with the waters travelling inland as far as Forfar.