How to deal with the bear, known as M13 by authorities, had sparked controversy between gamekeepers and environmentalists far outside the Graubuenden canton, which borders on Italy and Austria and where the animal was most often spotted.
Swiss gamekeepers said Mike, given the name by creators of a Twitter account set up to track him and spread his fame, had increasingly pushed into populated areas and shown no fear of people, presenting a major safety risk.
"The bear's behaviour couldn't be changed," wildlife wardens in the canton -- home to famous winter holiday resorts like St Moritz, Klosters and Davos -- said in a statement.
Mike's adventures, such as breaking into beehives belonging to a school in the town of Poschiavo, were closely monitored after he was fitted with a tracking device last June.
Sightings - including when he was hit by a train on the local Rhaetian Railway, a major tourist draw - became a staple in Swiss tabloids, and Mike's popularity grew when the Twitter account was set up.
Last year, the bear unwittingly led Austrian police to a murder victim when he started a fire by knocking a tree onto a power line.
But Swiss federal and local authorities decided he had to be put down after he broke into a Graubuenden home last November. In recent days, he had approached humans again after waking up from hibernation, game officials said.
The Swiss-based World Wide Fund for Nature (WWF) condemned the shooting, saying wardens should have instead intensified efforts to frighten the animal away from populated areas.
Several brown bears, including two called M12 and M14 who had been identified as Mike's brothers, have also been known to roam between Switzerland, Austria and Italy. M14 died last year when he was hit by a car.
(Reporting By Katharina Bart, editing by Paul Casciato)