The animals, a male and a female, were both spotted early Friday morning. Wildlife officials do not think the moose were travelling together.
Officers tried to tranquilize the one roaming near Marlborough Mall, but it became more agitated and went into a neighbourhood where it broke a fence.
Brendan Cox, a spokesman for Alberta Justice and the solicitor general, said there were a couple of close calls when the animal came too close to people.
Officers made the decision to kill the moose because it was posing a risk to human safety, he said.
The second moose is still loose in the Forest Lawn area east of 52nd Street.
Cox says because the female is in an industrial area, and is laying low, officers will just monitor the situation and hope she leaves the city are on her own.
On Thursday, officials announced that a government review has concluded Alberta Fish and Wildlife officers were were justified in fatally shooting a cougar at the South Health Campus in Calgary in September. That incident sparked a public outcry with many critics arguing the animal could have been tranquilized.
Correction : An earlier version of this story said the moose were companions, but wildlife officials now believe they were not travelling together.(Dec 05, 2014 4:09 PM)Suggest a correction