Stadden was born in Decatur, Illinois, in 2002. She grew up in Blaine, Minnesota, and attended Blaine High School.
At the 2018 USA Championships in July, Stadden won the bronze medal in the 200 m backstroke.
The following month, she competed at the 2018 Junior Pan Pacific Championships and won the gold medal in the 200 m backstroke with a championship record time of 2:09.52.[2]
Stadden competed at the 2019 Pan American Games in August. She won the silver medal in the 200 m backstroke.[3][4][5] She swam in the heats of the women's 4 × 100 m medley relay, and the U.S. finished first in the final, earning Stadden a gold medal.[5]
In December, Stadden won the gold medal in the 200 m backstroke at the 2019 U.S. Open.
Stadden enrolled at the University of California, Berkeley, and started competing for the California Golden Bears. At the 2021 NCAA Division I Championships in March, she won the bronze medal in the 200 y backstroke and finished fifth in the 100 y backstroke.
In June, Stadden competed at the 2021 U.S. Olympic trials. She finished fifth in the 100 m backstroke and fourth in the 200 m backstroke and did not qualify for the Olympic team.
In December, Stadden competed at the 2021 World Championships (25 m). She won the bronze medal in the 200 m backstroke.
At the 2022 NCAA Division I Championships in March, Stadden finished fourth in the 200 y backstroke and seventh in the 100 y backstroke.
In July, Stadden competed at the 2022 USA Championships. She won the gold medal in the 200 m backstroke and the bronze medal in the 100 m backstroke.
Stadden competed at the 2022 World Championships (25 m) in December. In the 100 m backstroke, she finished eighth. In the 200 m backstroke, she did not qualify for the final.
At the 2023 NCAA Division I Championships in March, Stadden won the bronze medal in the 200 y backstroke and finished sixth in the 100 y backstroke.
In July, Stadden competed at the 2023 USA Championships. She finished fifth in the 50 m backstroke, fifth in the 100 m backstroke, and sixth in the 200 m backstroke.
