- Source: Sonja Castelein
- Sonja Castelein
- Castelein
- List of Belgian Athletics Championships winners
- 1975 IAAF World Cross Country Championships – Senior women's race
- 1976 European Athletics Indoor Championships – Women's 1500 metres
- Lotto Cross Cup de Hannut
- 1974 European Athletics Championships – Women's 3000 metres
- Véronique Collard
- Lea Alaerts
- Golden Spike (Belgium)
Sonja Castelein (born 10 June 1954) is a Belgian middle-distance runner. She competed in the women's 1500 metres at the 1976 Summer Olympics.