During the 1936 Summer Olympics in Berlin, who became the first woman in the world to swim the Butterfly stroke in an official competition?

Martha Genenger

Martha Genenger was a German breaststroke swimmer winning the 1934 European Championships over 200m. At the 1936 Olympic Games in Berlin she won the silver medal and showed proudly the so-called Hitlergruß at the medal ceremony. From 1934-36 she was the German Champion in this event. During her active career she set two world records and claimed nine more German records. After World War II she was one of the co-founders of the swimming section of TV Kapellen in her home town Moers.
https://www.olympedia.org/athletes/47659.

https://en.wikipedia.org/wiki/Butterfly_stroke

Her name was Maria Emma Hulga Lenk. She was from Brazil & was the first woman from South America to participate in the Summer Olympics in 1932. From her wiki article:

"She also participated in the 1936 Summer Olympics, in Berlin, where she reached the semifinals of the 200m breaststroke event. In this occasion, she also became the first woman in the world to swim the Butterfly stroke in an official competition."



https://en.wikipedia.org/wiki/Maria_Lenk#Biography