Karsten Antonio Mielke was born in Recife, Brazil, on 2nd of November 1977 and grew up in Germany. As a young man he travelled through Europe and then settled in Berlin. He was trained as an actor in London and Berlin, and participated in courses at the Giles Forman Centre London (2006-2008) and at Actors Space Berlin (2008-2012) among others. During that time, Mielke appeared in several supporting roles in short films as well as in feature films, such as Wolfgang Eißler's "Berlin am Meer" ("Berlin by the Sea", 2006-2008), Thomas Sieben's "Distanz" ("Distance", 2009), Feo Aladag's "Die Fremde" ("When We Leave", 2010) and Michaela Schweiger's "Trabanten" (2010). He played a lead role in Mascha Schilinski's medium-length film "Das Gefühl" (2013) and collaborated with her again in her short "Die Katze" (2014). On TV, he starred in crime series such as "SOKO Wismar" (23013) and "Notruf Hafenkante" (2015).

His first lead role in a feature film was in another film by Mascha Schilinski. In "Die Tochter" ("Dark Blue Girl", 2017), he portrayed the father of a young girl who desperately tries to get in the way of her separated parents' reconciliation. For this role he received several awards, e.g. at the Evolution Filmfestival Mallorca and at the Cyprus International Film Festival. "Die Tochter" was released in German cinemas in May 2018. In the same year, Mielke played smaller roles in a number of TV productions, among them Markus Imboden's "Zeit der Frösche", an episode of the popular German crime series "Tatort", and in the crime series "Kommissarin Heller – Herzversagen".