Montague is a township in eastern Ontario, Canada, in Lanark County on the Rideau River.

The township administrative offices are located on Roger Stevens Drive east of Smiths Falls.

The township comprises the communities of Andrewsville, Atironto, Kilmarnock, Nolans Corners, Numogate, Poolers Corners, Rosedale and Welsh.

The Rideau Trail passes through the township between Merrickville and Smiths Falls.

This Eastern Ontario geographical article is a stub.