Ottawa River drainage basin
The Ottawa River drainage basin is the drainage basin in northern North America where surface water empties into the Ottawa River and adjoining waters. Spanning an area of about , it is the 12th largest drainage basin in Canada, occupying the Canadian provinces of Ontario and Quebec. It accounts for about 11% of the total Saint Lawrence River drainage area.
List of longest rivers of Canada
The primary source for data in the table below is "The Atlas of Canada"; other sources are as noted. Discharge refers to the flow at the mouth except as noted. U.S. states appear in italics. Abbreviations are as follows: "km" for "kilometre", "mi" for "mile", "s" for "second", "m" for "metre", and "ft" for "foot".