He comes off a year in which he racked up a career-best 53 tackles to go along with four quarterback traps.
Long-time Packers pass rusher Clay Matthews is set to become a free agent on Wednesday.
There is at least one prominent onetime PSU star staying put, however, as Tampa Bay tackle Donovan Smith has already signed a three-year, $41.5 million deal to remain with the Buccaneers.
Both additions help the Packers at arguably their two biggest weak points on the entire roster. General manager Ryan Pace made a similar decision Monday, deciding to sign veteran nickel back Buster Skrine instead of keeping Bryce Callahan, who figures to get a larger contract than the $8.5 million guaranteed and $16.5 total Skrine took home.
Amos grew into one of the best all-around safeties in the National Football League with the Bears, and now brings that ability to play in the box and roam around the back end to Green Bay, where he is desperately needed.
Smith joins the exodus of Baltimore defensive players.
Adrian Amos joins the Packers from NFC North rivals the Chicago Bears
The Packers are expected to pay Smith like an elite rusher.
Smith could be coming in at the same time another Kentucky star is on his way out of Green Bay. Amos is just 25 years old, and was drastically more affordable than Landon Collins on the open market.
Amos registered 73 tackles, nine pass breakups, two interceptions, two tackles for losses and one fumble recovery in 2018. He signed with the Packers for $52.2 million over four years ($13 million/year).
The people spoke to The Associated Press on condition of anonymity because the contracts can not become official until the new league year opens Wednesday.
Barr's surprising reversal lets Vikings keep key piece
The one big advantage the Vikings likely had in their negotiations is the fact that Barr is familiar with their defense. Pro Football Focus ranked Barr as their third highest rated free agent linebacker after Jordan Hicks and C.J.
Tesla pumps brakes on plan to shutter all stores
As part of that settlement, Musk stepped down as the company's chairman and he and Tesla agreed to pay $20m each in fines. Tesla announced on Sunday that it is reversing course on a plan to close all of its brick and mortar retail locations.