Joana Mäder (née Heidrich, born 2 October 1991) is a Swiss beach volleyball player.

She competed with Nadine Zumkehr in the 2016 Summer Olympics in Rio de Janeiro.

In July 2021, Heidrich and Vergé-Dépré represented Switzerland at the 2020 Summer Olympics in Tokyo and won the bronze medal.

They lost against Brazil's #1 seed team of Talita Antunes and Larissa França in a match of 3 sets (21–23, 27–25, 15–13), which was also the longest match at Rio, in the quarter-final played 14 August 2016 and settled at 5th place.

The duo played against fellow country mates of Isabelle Forrer and Anouk Verge-Depre in the semifinals and won in 3 sets of (14–21, 21–15, 15–10).