Several classes of ships have been called River class:

Destroyers of the Royal Navy built in the early 20th century that served in World War I.

• Canadian River-class destroyer
  Canadian River class destroyer
  The River class was a class of fourteen destroyers of the Royal Canadian Navy that served before and during the Second World War. They were named after Canadian rivers.-Description:...
  
  of the Royal Canadian Navy that served in World War II. - frigates built for the Royal Australian Navy post Second World War. of the Royal Australian Navy that served in the First World War.

Frigates of the Second World War built for the Royal Navy, Royal Canadian Navy and other navies.

Minesweepers of the modern Royal Navy.

Patrol vessels of the modern Royal Navy. of the Royal Navy.

Submarines of the interwar Royal Navy that saw service in World War II.