The 47-year-old will hang up his helmet after a Supercars career that included 14 seasons as a full-timer and 10 race wins.
Having made a 27th and final start alongside Mark Winterbottom at Team 18 this year, Richards will now move into a full-time Relationship Manager role with the squad as it expands to two cars for 2020.
“I’ve been in discussion with Charlie and the team regarding an active role for some time,” said Richards.
“It’s an exciting time at Team 18 and now is the right time to make this decision. I’ll be able to utilize my experience to assist [owner] Charlie [Schwerkolt] and the team drive success both on and off the track and work closely with the incredible team partnerships that have been established.
“I’ve had a fantastic career in Supercars, winning races, competing for championships, and driving with the best teams and drivers in the most competitive touring car championship in the world.
“While I close the door on Supercars I’ll still have some flexibility to continue driving in other categories.”
Schwerkolt added that moving Richards from a driving role into a commercial role will help future-proof the Holden team.
“Really sad day for us to announce Richo is hanging up the helmet on his Supercars career, but his move into the management and commercial side of Team 18 will be great future-proofing for the team,” he said.
“We have been chatting about this for a while when Richo first joined the team at the start of the year, but now with the expansion to a two-car operation, the role has really progressed into a full-time role.
“Richo has extensive motorsport knowledge and it’s a massive get for our team to have someone of his calibre that can guide and assist all Team 18 properties. I’m really, really proud to have him on board.”