Having grown up in a theatre family, Catharina Fleckenstein's path also led her to the theatre. After permanent engagements in Bamberg and Dortmund, she worked for several years as a director at various municipal theatres.

Since the turn of the millennium, she has concentrated on her acting work.

She has appeared in film and television productions and in various theatre productions in Hamburg. 
Most recently at the Theatersommer in the Concert Park of the Kulturforum Lüneburgas Marthe and in other roles in Goethe's "Faust".