The inspirational Du Plessis is finally back to full fitness after the horrendous knee injury he suffered against Argentina last year and is reunited with his prop brother Jannie in a front row which will aim to hammer the Wallabies at scrum time.
Like Du Plessis, lock Flip van der Merwe moves up from the bench in place of Juandre Kruger in another change for the Lang Park clash, while Zane Kirchner will play his first Test of the year at fullback after recovering from a hand injury.
Coach Heyneke Meyer made two positional changes to clear the way for Kirchner's return, moving Willie le Roux from full-back to the right wing with Bryan Habana, who scored a hat-trick against Australia in Pretoria last year, shifting to the left.
Promotions for Du Plessis and Van der Merwe mean Adriaan Strauss and Kruger drop to the bench, while winger Bjorn Basson drops out of the team altogether after starting in the two wins over Argentina with which South Africa opened their campaign.
"A few of these changes are purely rotational in order to give guys with fresh legs a go, while others are simply a case of horses for courses," Meyer said.
"We're fortunate to be in a position to rotate players of the calibre of Bismarck and Adriaan, while we felt this was the right opportunity to give Flip and Zane a go in the starting team.
"In the end, the most important factor still remains consistency in selection. In our squad, any player can slot in at any stage, and that is a good position to be in."
Kruger was the only one of the five players in the matchday squad who have controversially made the long journey from Europe to play a full match in France's Top 14 last weekend.
The physical toll of the long journey on Habana, prop Gurthro Steenkamp, fly-half Morne Steyn and scrum-half Jano Vermaak is bound to be closely monitored by those in South Africa resolutely opposed to picking those playing overseas.
After a record 73-13 win over the Pumas in their opening fixture in Soweto, the Springboks struggled to a 22-17 victory in the reverse match in Mendoza two weeks ago.
They have never beaten Australia in seven attempts at Lang Park and have lost five of their last six tests against the Wallabies.
"If we are going to progress as a team, we need to start winning away from home and Saturday's test provides this challenge," Meyer added.
"It's no use looking at history now - we have to focus on the test, ensure we tick the right boxes and improve in the areas where we let ourselves down in Mendoza."
Team: 15-Zane Kirchner, 14-Willie le Roux, 13-JJ Engelbrecht, 12-Jean de Villiers (captain), 11-Bryan Habana, 10-Morne Steyn, 9-Ruan Pienaar, 8-Duane Vermeulen, 7-Willem Alberts, 6-Francois Louw, 5-Flip van der Merwe, 4-Eben Etzebeth, 3-Jannie du Plessis, 2-Bismarck du Plessis, 1-Tendai Mtawarira
Replacements: 16-Adriaan Strauss, 17-Gurthro Steenkamp, 18-Coenie Oosthuizen, 19-Juandre Kruger, 20-Siya Kolisi, 21-Jano Vermaak, 22-Pat Lambie, 23-Jan Serfontein.