The role was vacated by Steve Henderson ahead of the 2022 season, with John Moore standing in for the first four rounds.
A permanent appointment has now been made with experienced race team boss Beasley stepping into the role.
Beasley owns and runs the MTEC Motorsport outfit in the Toyota Racing Series and was previously the team manager at Erebus Motorsport.
Most recently he was operations manager at the Winton Motor Raceway.
He will make his debut for Team 18 at the very same circuit this weekend for the Winton SuperSprint.
“I’m really thrilled to join Team 18 as team manager," said Beasley.
“Charlie has brought in a group of really talented people from our drivers and engineers to mechanics and support staff, so I hope I can bring my experience from working with other professional outfits around the world to deliver some strong results for the team on track.
“It’s exciting to get back into the Supercars paddock. It really is one of the toughest racing series in the world with the quality of competition and we know Scott [Pye] and Mark [Winterbottom] can fight right up there with the best of them.
“I’m looking forward to kicking off with the team this weekend at Winton and working to achieve great things into the future.”
Team owner Charlie Schwerkolt said hiring Beasley is part of the team's push to take its performance "to the next level".
“It’s an exciting time to welcome Bruin Beasley as our team manager moving forwards at Team 18," he said.
“His experience from managing successful teams in various categories in Australia and around the world will bolster our personnel here at Team 18 as we look to push our performance to the next level.
“No doubt it’s been an up and down start to the year for us with a couple of incidents that have stunted our forward progress, but we’ve seen glimpses of strong results when we put it all together and we know the drivers in our stable are capable of competing at the front in this championship.
“We’re looking forward to Bruin’s arrival as we look to hit the ground running at Winton.”
