Davies, who made his debut against South Africa in 2014, will continue his partnership with Dan Biggar at half-back for the game in Yokohama.
Jonathan Davies returns from injury to line-up in the midfield alongside Hadleigh Parkes whilst Leigh Halfpenny comes into the starting line-up at full-back in place of injured Liam Williams to earn his 85th cap. Halfpenny will link up with Josh Adams and George North in the back-three.
Wyn Jones, Ken Owens and Tomas Francis once again comprise the front-row, the fifth time they have started together in this tournament.
Captain Alun Wyn Jones, who packs down alongside Jake Ball in the second-row, will move to joint-second on the all-time international appearance list on Sunday, level with Sergio Parisse on 142 tests (133 for Wales plus 9 British & Irish Lions appearances).
Aaron Wainwright, who has featured in every game for Wales at Japan 2019 lines up at six alongside Justin Tipuric and Ross Moriarty.
On the bench Elliot Dee, Rhys Carre and Dillon Lewis provide the front-row cover with Adam Beard and Aaron Shingler completing the forward contingent. Tomos Williams, Rhys Patchell and Owen Watkin provide the backline cover.
WALES TEAM TO PLAY SOUTH AFRICA ON SUNDAY OCTOBER 27:
1. Wyn Jones (Scarlets) (20 Caps)
2. Ken Owens (Scarlets) (71 Caps)
3. Tomas Francis (Exeter Chiefs) (47 Caps)
4. Jake Ball (Scarlets) (40 Caps)
5. Alun Wyn Jones (Ospreys) (132 Caps) (CAPT)
6. Aaron Wainwright (Dragons) (17 Caps)
7. Justin Tipuric (Ospreys) (70 Caps)
8. Ross Moriarty (Dragons) (39 Caps)
9. Gareth Davies (Scarlets) (49 Caps)
10. Dan Biggar (Northampton Saints) (77 Caps)
11. Josh Adams (Cardiff Blues) (19 Caps)
12. Hadleigh Parkes (Scarlets) (23 Caps)
13. Jonathan Davies (Scarlets) (79 Caps)
14. George North (Ospreys) (90 Caps)
15. Leigh Halfpenny (Scarlets) (84 Caps)
Replacements:
16. Elliot Dee (Dragons) (27 Caps)
17. Rhys Carre (Saracens) (4 Caps)
18. Dillon Lewis (Cardiff Blues) (20 Caps)
19. Adam Beard (Ospreys) (18 Caps)
20. Aaron Shingler (Scarlets) (24 Caps)
21. Tomos Williams (Cardiff Blues) (14 Caps)
22. Rhys Patchell (Scarlets) (17 Caps)
23. Owen Watkin (Ospreys) (20 Caps)
