| Gian Mamuyac | |
| Number: | 3 |
| Position: | Shooting guard |
| League: | PBA |
| Team: | Rain or Shine Elasto Painters |
| Nationality: | Filipino |
| Birth Date: | 5 March 1999 |
| Birth Place: | Quezon City, Philippines |
| Height Ft: | 6 |
| Height In: | 2 |
| Weight Lbs: | 165 |
| High School: | Ateneo (Quezon City) |
| College: | Ateneo |
| Draft Year Pba: | 2022 |
| Draft Round Pba: | 1 |
| Draft Pick Pba: | 5 |
| Draft Team Pba: | Rain or Shine Elasto Painters |
| Career Start: | 2022 |
| Years1: | 2022–present |
| Team1: | Rain or Shine Elasto Painters |
| Highlights: |
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Gian Robert J. Mamuyac (born March 5, 1999) is a Filipino professional basketball player for the Rain or Shine Elasto Painters of the Philippine Basketball Association (PBA).
Mamuyac was selected 5th overall pick by the Rain or Shine Elasto Painters in 2022 PBA draft.[1] [2] As a rookie, he earned his first PBA All-Star Game selection in 2023.[3] [4]
As of the end of 2023–24 season[5]
|-| align=left | | align=left | Rain or Shine| 30 || 21.8 || .432 || .269 || .744 || 3.0 || 2.1 || 1.1 || .2 || 9.9|-| align=left | | align=left | Rain or Shine| 29 || 22.0 || .494 || .222 || .681 || 2.8 || 2.4 || .9 || .2 || 10.7|-class=sortbottom| align="center" colspan=2 | Career| 59 || 21.9 || .463 || .251 || .710 || 2.9 || 2.3 || 1.0 || .2 || 10.3