Jason Archinaco, the homeowner in the hilly Los Feliz neighborhood, told a television station workers installing a home security system encountered the cougar in a crawl space around noon Monday. He was still there more than 10 hours later.
"I don't think he's going to come out," Archinaco said. "He's probably been living here for a while. ... He thinks this is his den."
The animal, which has a red ear tag, is known as P-22 and normally lives in nearby Griffith Park. It arrived in the area several years ago from the Santa Monica Mountains and crossed two freeways to get there.
National Geographic famously photographed P-22 in 2013 with the Hollywood sign in the background, and several sharp photographs from a remote camera in Griffith Park captured the cat last year.
He survived mange and a meal of rat poison last year to become apparently healthy again.
At the home, state wildlife officials cleared most media and gawkers away after darkness fell, then used several techniques to try to get him to move.
They poked him gently with a long prod, but that did little - other than temporarily lose the pricey GoPro camera they had attached to the end of it.
They fired a tennis ball cannon into the crawl space with hopes that at least the noise and commotion would scare him out, a tactic that often works with coyotes.
They then fired small bean bags, the same kind police sometimes use for human crowd control, toward the cat.
All the tactics, shown live on streaming video, drew mild reactions from P-22 - none coming close to drawing him out or even getting him to move much.
Wildlife officials said late Monday that their next move would be to just wait.
"We're going to let him settle, we're going to let everything calm down, we're going to be really still and give him time to get out of there," said Janice Mackey of the California Department of Fish and Wildlife.
Archinaco said he and his wife have three ordinary house cats and had thought about adding to their numbers.
"My wife wanted a fourth one," he said, "but not this way."
I must admit, I never thought the most famous resident of my district would be #P-22.— Mike Gatto (@mikegatto) April 14, 2015
The Associated Press contributed to this report.