Westwood has played in the past 10 contests since making his debut in 1997 and was on the winning side seven times, while Harrington was vice-captain to Paul McGinley in 2014 and Darren Clarke in 2016. McDowell, who claimed the winning point at Celtic Manor in 2010, and Donald will make their debuts as vice-captains at Le Golf National in Paris on Sept. 28 as Europe seek to regain the trophy following defeat at Hazeltine two years ago.
Bjorn, who had already selected Sweden's Robert Karlsson as a vice-captain, said: "All five are widely respected throughout the game, are all current players who are well known to the players who will be in our team come September and they also all possess a knowledge and understanding of what to expect from the golf course at Le Golf National, too.
"You only need to look at the record books to see that their Ryder Cup pedigree speaks for itself. Each of them has played both home and away, so they are well versed in the contest and know how to handle the special and unique atmosphere.
"They all possess strong personalities, but each of them will also bring something different to the team, giving us great balance. They have forthright opinions, which is vital under the spotlight of a Ryder Cup week and is something which can only help our cause as we try and regain the trophy."
Westwood, who along with Harrington has expressed an interest in the captaincy in the future, "jumped at the chance" to join Bjorn's backroom staff.
"When Thomas asked me to take that role I was obviously delighted and jumped at the chance," Westwood said. "Myself and Thomas have known each other many years, and anything I can do to have a bit of input and help, I will gladly do, and it will be nice to see him take on his role as captain and support him as much as I can.
"Playing in a Ryder Cup is very special. But to be involved with it is very special as well and something I want to do."