| Birth Date: | 9 June 1960 |
| Birth Place: | Bangkok, Thailand |
| Death Place: | Johns Hopkins Hospital, Baltimore, Maryland, US |
| Office: | Thai Ambassador to the United States |
| Term Start: | June 2018 |
| Term End: | March 16, 2019 |
| Succeeded: | Thani Thongphakdi |
| Preceded: | Pisan Manawapat |
| Education: | University of Paris (LL.B, LL.M., PhD) |
| Native Name: | วีรชัย พลาศรัย |
| Native Name Lang: | th |
| Primeminister: | Prayut Chan-o-cha |
| Office1: | Thai Ambassador to the United Nations |
| Termend1: | 2018 |
| Termstart1: | 2015 |
| Succeeded1: | Vitavas Srivihok |
Virachai Plasai was a Thai diplomat who served as Thai Ambassador to the United States from 2018 to 2019.[1] Plasai previously served as Thai Ambassador to the United Nations from 2015 to 2018 and Thai Ambassador to the Netherlands from 2009 to 2015.[2] Plasai died on March 16, 2019, while being treated for myelodysplastic syndrome.[3] [4]