The Ontario Beverage Network, an provincial beer industry publication, has a cool database and map of all independent breweries in Ontario.
It can be sorted based on factors such as city, whether the brewery also serves food or even if they offer mail delivery (quite a few do!)
According to the OBN’s list, there are 22 craft brewers operating in Ottawa. Try it out on ontariobev.net.
Updated from October 2017.