| Birth Date: | 13 April 1920 |
| Birth Place: | Amsterdam, the Netherlands |
| Death Date: | 5 July 1979 |
| Death Place: | Enkhuizen, the Netherlands |
| Sport: | Swimming |
| Club: | ADZ |
| Show-Medals: | yes |
Johanna Maria Elisabeth "Jopie" Waalberg (13 April 1920 – 5 July 1979) was a Dutch breaststroke swimmer who competed in the 1936 Summer Olympics and was the first woman to swim the 200 meter breaststroke under 3 minutes.[1] [2]
In 1936 she finished fifth in the 200 metre breaststroke event, the single breaststroke event until the 1968 Olympics. At the 1938 European Aquatics Championships in London she won a bronze medal on the same distance.
On May 11, 1937 she broke Hideko Maehata's four-year-old breaststroke record by 0.2 seconds (3:00.2). On Jun 27 of that year, in Zaandijk, she improved on that record by more than 2 seconds to 2:58.0. She improved her own world record once more on October 2 to 2:56.9. She further held world records in the unconventional distances of 200 yard, 400 m and 500 m breaststroke.