Among those missing through injury are lock Lood de Jager, halfback Faf de Klerk, prop Steve Kitshoff, halfback Herschel Jantjies, utility back Damian Willemse, centre Canan Moodie, and lock Franco Mostert.
Centre Andre Esterhuizen is also missing as he faces a disciplinary hearing after being sent off against Portugal at the weekend.
Hooker Malcolm Marx has been included, although he suffered a leg bone injury in South Africa's win over Ireland 10 days ago.
Some in South Africa see de Klerk's absence as a sign of a potential change in tactics from halfbacks. Those chosen, Morne van den Berg, Grant Williams and Cobus Reinach, are regarded as speed merchants who could continue South Africa's recent development of a more expansive game.
No8 shapes as a position of interest as the Springboks prepare to play Australia in their opening two games.
Jasper Wiese is under suspension, while Evan Roos, who filled the position against Portugal at the weekend, was not included in the squad. Kwagga Smith played No8 in the series against Ireland.
Coach Rassie Erasmus said, "This is a quality group of players, which includes a mixture of youth and experience, and we believe this is the best group of players we could select for this tough assignment in the Rugby Championship.
"We rested some players before the match against Portugal to recharge for this competition and we are excited to see the energy they'll bring to the squad. We've also included a few younger players who made a strong statement in the Tests we've played so far this season."
Erasmus said players who missed the final 33 have been placed on specialised conditioning programmes because the squad to play New Zealand could be different to that named for Australia.
South Africa's squad is:
Forwards:
Ben-Jason Dixon (Stormers), Pieter-Steph du Toit (Toyota Verblitz), Thomas du Toit (Bath), Eben Etzebeth (Sharks), Johan Grobbelaar (Bulls), Vincent Koch (Sharks), Siya Kolisi (captain - Racing 92), Elrigh Louw (Bulls), Frans Malherbe (Stormers), Malcolm Marx (Kubota Spears), Bongi Mbonambi (Sharks), Salmaan Moerat (Stormers), Ox Nche (Sharks), Ruan Nortje (Bulls), Kwagga Smith (Shizuoka Blue Revs), RG Snyman (Leinster), Gerhard Steenekamp (Bulls), Marco van Staden (Bulls), Jan-Hendrik Wessels (Bulls).
Backs:
Lukhanyo Am (Sharks), Kurt-Lee Arendse (Bulls), Damian de Allende (Wild Knights), Aphelele Fassi (Sharks), Sacha Feinberg-Mngomezulu (Stormers), Cheslin Kolbe (Suntory Sungoliath), Jesse Kriel (Canon Eagles), Willie le Roux (Bulls), Makazole Mapimpi (Sharks), Manie Libbok (Stormers), Handré Pollard (Leicester Tigers), Cobus Reinach (Montpellier), Morne van den Berg (Lions), Grant Williams (Sharks).