| Birth Place: | Renesse, the Netherlands |
| Height: | 1.66m (05.45feet) |
| Weight: | 58kg (128lb) |
| Sport: | Diving |
| Club: | Joop Stotijn, Den Haag |
| Show-Medals: | yes |
Dorothea Dirkje Jacoba "Thea" du Pon (later Sjoerdsma, born 27 November 1943) is a retired Dutch diver. She competed at the 1960 Summer Olympics in the 3 m springboard and finished in eighth place. She and her sister Judith were national springboard champions around 1960.