Anna Christina Maria "Christl" Mardayn (8 December 1896 in Vienna – 24 July 1971) was an Austrian actress and singer.
After graduation she studied piano, dance and song at the Academy of Music and Dramatic Arts in Vienna.
She sang Cherubino in Le nozze di Figaro, Lola in Cavalleria rusticana, and Sieglinde in Die Walküre.
She starred in the title role of Franz von Suppé's operetta Die schöne Galathee around 100 times.
In 1921, the soubrette moved to the Raimund Theater and in 1922 went to the Charles Theatre, where she sang in premiere performances of operettas such as Die Bajadere by Emmerich Kálmán, The Dragonfly Dance by Franz Lehár and The Lady in Ermine by Jean Gilbert.