Larissa Keat was born in Lenzburg as the elder of two daughters with an American father and a Swiss mother. Since 2013 she has lived in Hamburg where she had moved for her acting education.

After graduating drama school she has been working as a freelance actress and performer for example at Deutsches Schauspielhaus Hamburg (director: Schorsch Kamerun) or Kampnagel Hamburg (choreography: Patricia Carolin Mai). She has also worked at theaters in Switzerland quite frequently, such as Junges Schauspielhaus Zürich or DAS Theater an der Effingerstrasse in Bern.

Another part of her artistic work is her engagement in the off scene. She has written and staged several own plays (#DieKapsel, NowHere Land).
With the performance Rally against Radicalisation in Marrakech and Marseille it was the first time she worked outside the German speaking part of Europe.