In a video he released for his 2010 campaign volunteers, Nenshi broke the news just ahead of this afternoon's media announcement.
“I'm pleased to announce today that I will be a candidate in the next municipal election in October 2013," he said in the video.
"I’m in! I am in with everything I’ve got. I’m in because I still love this city, if possible even more than I did two years ago and I’m in because we have the opportunity to build something even better.”
Nenshi pulled a come-from-behind victory in 2010 over a crowded field of candidates to become Calgary's mayor.
Several members of city council have told CBC News today they are not surprised that Nenshi says he wants to keep the job.
Today's announcement ended months of speculation.Suggest a correction