Ottawa is about 1.4 times smaller than Melbourne.

Melbourne (the 27 councils of metropolitan Melbourne, without the Yarra Ranges, Cardinia, Mornington Peninsula and Nillumbik) is approximately 3,915 sq km, while Ottawa is approximately 2,779 sq km, making Ottawa 70.97% the size of Melbourne.
Tip: This to-scale comparison of Melbourne vs. Ottawa uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.