| Thomasau Forbes | |
| Fullname: | Thomasau Roberto Forbes |
| Birth Date: | 12 October 1988 |
| Birth Place: | Swakopmund, South West Africa |
| School: | Namib High School |
| University: | Nelson Mandela Metropolitan University |
| Position: | Flanker |
| Youthyears1: | 2007–2009 |
| Years1: | 2015–present |
| Apps1: | 24 |
| Points1: | 5 |
| Repyears1: | 2010–2017 |
| Repcaps1: | 17 |
| Reppoints1: | 15 |
| Clubupdate: | 22 July 2018 |
| Repupdate: | 14 September 2019 |
Thomasau Roberto Forbes (born 12 October 1988) is a Namibian rugby union player for the in the Currie Cup and the Rugby Challenge. His regular position is flanker.
Forbes was born in Swakopmund (then in South-West Africa, but part of modern-day Namibia). He made his test debut for in 2010 against and represented the in the South African domestic Currie Cup and Vodacom Cup since 2015.