Ben Donaldson, who had started the past three Tests at flyhalf, has been ruled out of Saturday's Bledisloe Cup clash at Allianz Stadium with a "minor upper leg injury".
His absence has set the scene for Meredith's third career start, fresh off a shaky cameo off the bench in the All Blacks' Cup-retaining 50-19 win in Auckland last week.
With Carter Gordon and Tom Lynagh both sidelined by injury, Harry McLaughlin-Phillips is poised for a Test debut off the bench as the replacement playmaker in a call coach Les Kiss said was made 90 minutes before the team was announced on Thursday.
Meredith debuted against France in July as the Wallabies' seventh different flyhalf in the past 17 Tests, with injuries largely behind the mass turnover.
"I've got a lot of trust in what he's got in his game, he takes the line on, good kicking game, very solid defender," Kiss said.
"And he (McLaughlin-Phillips) is a physical 10, just like Declan."
Kiss said he had spoken to veteran prop James Slipper and experienced playmakers James O'Connor, Kurtley Beale and Bernard Foley - all playing Super Rugby Pacific next year - but that now was the time to test the next generation.
"It's an opportunity for other guys to be feeling it, tasting what Test rugby's about, not only the playing environment, but the training environment as well,'' he said.
"While we've got that opportunity, we'll use it.
"Those boys have been through the mill, we know what we can expect from them."
In some welcome news, form lock Josh Canham will return from injury to bolster the bench, while Carlo Tizzano has also been recalled.
Angus Bell's shift from the starting front row to the pine - in a straight swap with Aidan Ross - will also provide late-game punch.
Kalani Thomas has replaced Queensland Reds teammate Tate McDermott as the back-up scrumhalf, with Billy Pollard also on the bench and Josh Nasser the starting hooker.
Isaac Henry and Joseph-Aukuso Suaalii will start in the centres as expected, with midfielders Hunter Paisami (suspended) and Len Ikitau (concussed) unavailable.
The Wallabies scored first and trailed 17-14 at halftime before the hosts piled on the points to cement their 24-year grip on the Bledisloe Cup and make it 12 straight wins over Australia.
The All Blacks have also been forced into changes after copping four injuries in last week's Eden Park thumping.
Prop George Bower moves from the bench to start at loosehead, and lock Fabian Holland joins Scott Barrett in the second row.
Wing Josh Moorby will start, while hooker Samisoni Taukei'aho, prop Xavier Numia, loose forward Du'Plessis Kirifi, scrumhalf Cortez Ratima and midfielder Timoci Tavatavanawai have all been added to the bench.
WALLABIES: Aidan Ross, Josh Nasser, Allan Alaalatoa, Jeremy Williams, Lukhan Salakaia-Loto, Rob Valetini, Fraser McReight, Harry Wilson, Ryan Lonergan, Declan Meredith, Harry Potter, Isaac Henry, Joseph-Aukuso Suaalii, Max Jorgensen, Tom Wright. Bench: Billy Pollard, Angus Bell, Massimo De Lutiis, Josh Canham, Carlo Tizzano, Kalani Thomas, Harry McLaughlin-Phillips, Filipo Daugunu.
ALL BLACKS: George Bower, Codie Taylor, Fletcher Newell, Scott Barrett, Â Fabian Holland, Tupou Vaa'i, Peter Lakai, Wallace Sititi, Cam Roigard, Damian McKenzie, Josh Moorby, Jordie Barrett, Quinn Tupaea, Will Jordan, Beauden Barrett. Bench: Samisoni Taukei'aho, Xavier Numia, Pasilio Tosi, Shannon Frizell, Du'Plessis Kirifi, Cortez Ratima, Timoci Tavatavanawai, Rieko Ioane.
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