There are many farmer's markets in and around Ottawa through the week. The main market, on Sundays, has in the past been up at Lansdowne Park, but with the construction there, has been over at Brewer Park in Old Ottawa South for the time being. It's a busy place to wander through, with over a hundred vendors of produce, crafts, and meals at the peak of the season. Starting in May, it runs well into November here. You can stop in at several different places for a bite to eat (I recommend the farmer's breakfast, because after that, you will not need lunch).
The rule here is that the venders must grow their own goods; there's no buying and reselling that you see in some other markets, such as the Byward Market. And the majority of the venders are from within a hundred miles of the city, aside from one or two, for example, who bring in plums and peaches from southern Ontario. Such fruits simply don't grow in this part of the country.
It's a great area to walk through, find some fresh food along the way, have a meal, chat with people, and get your hands on tasty baking. I'm here each week for something or another, all the more convenient, given that it's so close to home.
And of course dogs are welcome. You'll see them with their humans, walking about, wagging their tails, pleased to see so many people and dogs... entranced by the smells of food, and even drooling. Like this magnificent fellow. Can you blame him?