Paradise Canyon Elementary School, at 471 Knight Way, was locked down for about 30 minutes when the black bear was sighted in the area around 3 p.m.
The female bear, estimated at about 125 pounds, was located in a back yard and was tranquilized near Baptiste Way and Crown Avenue. Sheriff's and Fish and Wildlife personnel were on scene.
"Schools were getting ready to be let out, so that was kind of a more of an emergency situation where Fish and Wildlife had to sedate the bear," said L.A. County Sheriff's Sgt. Burton Brink.
The bear had been spotted intermittently in the area throughout the day.
"We've had a lot of bears here in La Canada since the Station Fire," said local resident Scott Sevin. "Because there's like no vegetation, no food up there, anything, so when they come out of hibernation, they come down here."
The tranquilized bear was being transported into the Angeles National Forest where it would be set free.
No one was injured.