The 38-year-old loose forward began his Super Rugby career in 2006 when he debuted for the Highlanders.
Following his 67 caps for the Highlanders, Thomson headed offshore to Japan on a two-year contract with the Cannon Eagles before he returned to Super Rugby in 2015 for the Queensland Reds.
After 15 appearances for the Reds he moved to Melbourne in 2016, where he notched up 13 caps for the Melbourne Rebels.
In 2017 Thomson returned to Japan to once again play for the Cannon Eagles, however, was bedridden in Tokyo after suffering from lumbar discitis, a painful infection of the spine.
Thomson made his comeback last year in the Major League with the Utah Warriors before returning home to play for his old province Otago.
He was called into the Chiefs earlier this year as an injury replacement player.
Thomson said it has been an exceptional journey to reach 100 Super Rugby games.
"It's pretty crazy, I let this dream go a while ago, so to do it at this age with a team like the Gallagher Chiefs is pretty special and I am very much looking forward to it.
"I would not have believed it a couple of years back, but I am just grateful to be playing at this level. Every day for me is a bonus and this is a great environment to be in and however I can contribute whether that is playing or off the field that is what I will do."
Chiefs head coach Warren Gatland said Thomson brought a wealth of knowledge and experience.
"We are privileged as a club to play our role in this achievement and we are grateful to have his services. Reaching this milestone is no small achievement and we are looking forward to celebrating this great milestone on Sunday."
Thomson has been named on the bench for the Chiefs to face the Blues on Sunday at Eden Park.
1. Reuben O'Neill
2. Bradley Slater
3. Nepo Laulala
4. Tupou Vaa'i
5. Mitchell Brown
6. Lachlan Boshier
7. Sam Cane ©
8. Pita Gus Sowakula
9. Brad Weber
10. Kaleb Trask
11. Solomon Alaimalo
12. Alex Nankivell
13. Anton Lienert-Brown
14. Sean Wainui
15. Damian McKenzie
16. Samisoni Taukei'aho
17. Ollie Norris
18. Ross Geldenhuys
19. Adam Thomson
20. Mitchell Karpik
21. Lisati Milo-Harris
22. Aaron Cruden
23. Quinn Tupaea