Sonny Bill back in black
Williams, a member of the World Cup winning 2011 and 2015 All Blacks, opted out of Super Rugby this year to focus on Sevens, but will be rushed back into the side straight after the Rio Olympics.
He will miss the first Test against Australia in Sydney on August 20, and head coach Steve Hansen said what shape he is in physically and mentally will determine whether he plays the second Test a week later.
Savea has been retained although he was out of form in the June series against Wales and has not been able to make the Super Rugby finalists Wellington Hurricanes starting line-up for the past two weeks.
"We're confident that we've picked the right players for the Championship," Hansen said when naming his squad for the series, which also includes South Africa and Argentina.
"The form of the players in Super Rugby has been outstanding and, whilst there is not a lot of change from the [Wales series] squad, it was still a challenging team to select.
"It was more a case of who do we leave out, rather than who do we pick."
The return of Williams has been at the expense of Seta Tamanivalu who made his debut against Wales.
Damian McKenzie, the Chiefs fullback who had a stellar year in Super Rugby and was also a member of the All Blacks' June squad, has also been left out.
Hansen, who recently confirmed he will stay at the helm of the All Blacks through to the 2019 World Cup, said the number one goal was to win the championship but there were other considerations.
"The second goal is to grow the understanding and confidence of our newer players, both on and off the track," he said.
"The quality of the opposition we'll face during the Rugby Championship will require a growth in our physicality, intensity and the standard of our preparation. How well we do that will be reflected in our results.
"By the end of the tournament, we'd expect to have a greater understanding of where the 32 individual players are at, and their ability to cope and perform at Test level."
The squad of 18 forwards and 14 backs includes five players from the Hurricanes, who will play the Lions of South Africa in the Super Rugby Final on Saturday.
There are nine players from the Crusaders, seven Highlanders, six Chiefs and five Blues.
New Zealand squad:
Forwards: Dane Coles, Codie Taylor, Nathan Harris, Wyatt Crockett, Charlie Faumuina, Owen Franks, Joe Moody, Ofa Tu'ungafasi, Brodie Retallick, Luke Romano, Patrick Tuipulotu, Samuel Whitelock, Sam Cane, Elliot Dixon, Jerome Kaino, Kieran Read (captain), Ardie Savea, Liam Squire.
Backs: Tawera Kerr-Barlow, TJ Perenara, Aaron Smith, Beauden Barrett, Aaron Cruden, Lima Sopoaga, Ryan Crotty, Malakai Fekitoa, George Moala, Sonny Bill Williams, Israel Dagg, Waisake Naholo, Julian Savea, Ben Smith.
Agence France-Presse
