This place is one the reasons I love Toronto so much, there is always some kind of event going on here. Of course among my favorites are all the Christmas themed events here, but the concerts, and free movie nights are always nice. I work in Marketing so I appreciate all the colourful ads I feel is really makes this place seem a little more alive. Plus some of these ads are really creative.
There is no short list of events happening here, there are also quite a bit of street performers and busker going on a regular basis. All this activity makes this square really come alive! I love all the summer activities that happen here like the music concerts or the outdoor movies. Then during the winter time my favorite thins is the Christmas choirs that come perform here, Christmas is my favorite holiday and I love to explore what this great city has to offer.
While the Dundas Square can be quite touristy during the summer month and it can get really full of people, it still a nice place to visit. My favorite time to come here is during the winter as the night time starts earlier so the bright light stay on longer. Just remember that there is always traffic and underground parking is a must.