The now V8 Supercars star will drive alongside Sonic's regular Elite Class runner Adrian Mastronado in the two 60 minute races.
The move comes eight years after Slade finished second in the Australian Formula Ford Championship with the Victorian based team.
“We're really excited that Sladey's back,” said Sonic owner Mick Ritter.
“The Pro-Am is a great concept and it gives Tim the opportunity to return to our team and drive these great cars.”
Slade is the latest high-profile confirmation for the Phillip Island event, which counts as the third round of the Carrera Cup Australia.
“I did the Pro-Am race with Marc Cini last year and I really enjoyed it,” said Slade.
“I had some frustrations in my (V8) Supercar world (at Erebus Motorsport) at that point so it was good to do a one-make series event.
“When I found out that Mick (Ritter) was re-entering Carrera Cup this year I immediately asked him about the Pro-Am and if we could put a deal together.”
Ritter also confirmed that Rodney Jane and Ryan Simpson will join Nick McBride and Nick Foster respectively in his team's remaining entries.
Simpson meanwhile campaigns a Sonic-run Ford Falcon in the Kumho V8 Touring Car Series, having previously raced for the team in Formula Ford.
Foster and McBride sit third and fourth respectively in the Carrera Cup Australia after two rounds, trailing leader Warren Luff and second-placed man Steven Richards.