| Nationality: | New Zealander |
| Birth Date: | 16 March 1990 |
| Birth Place: | Johannesburg, South Africa[1] |
| Country: | New Zealand |
| Weight Class: | 70 kg, 78 kg |
| Olympics Rank: | R32 |
| Olympics Year: | 2012 |
| Olympics Weight: | Women's 70 kg |
| Olympics Year2: | 2024 |
| Olympics Weight2: | Women's 78 kg |
| Worlds Rank: | R16 |
| Worlds Year: | 2022 |
| Worlds Weight: | Women's 78 kg |
| Worlds Year2: | 2023 |
| Worlds Weight2: | Women's 78 kg |
| Regionals Type: | OC |
| Regionals Rank: | 1 |
| Regionals: | (× 8 times) (2023) |
| Commonwealth Rank: | 2 |
| Commonwealth Year: | 2014 |
| Commonwealth Weight: | Women's 70 kg |
| Updated: | 3 August 2024 |
Moira de Villiers (born 16 March 1990), also known by her married name of Koster, is a South African-born New Zealand judoka.[2] She competed in the 70 kg event at the 2012 Summer Olympics losing in the first round.[3] She competed in the women's 70 kg event at the 2014 Commonwealth Games where she won the silver medal.[4]
De Villiers is married to Jason Koster; he is also a judoka.[5] They have a daughter together and her husband has a son from a previous relationship.[6]