In 2004, Daniel Zillmann made his cinema debut in Leander Haußmann's film NVA. Further roles in TV and cinema productions such as Die Känguru-Chroniken, Andere Eltern and Der gleiche Himmel followed. Frank Castorf brought the actor to the Volksbühne Berlin in 2014. In Baumeister Solness, he shone in a dual role as Mrs. Solness and Ragnar Brovik. Also under Castorf's direction, he played Alexei in Dostoevsky's The Brothers Karamazov and Zacharie Moyron in The Cabal of the Hypocrites. In 2017, Daniel Zillmann premiered at the Schauspielhaus in Hamburg with the play Ich kann nicht mehr, directed by René Pollesch, and as Monsieur Bordenave in Frank Castorf's Faust at the Volksbühne Berlin. The following year, he appeared at the Salzburg Festival in the play Hunger, directed by Frank Castorf and based on Knut Hamsuns novel of the same name. Since 2019, Daniel Zillmann has been writing his own column My fabulous life as a fat actor for Curvy Mag. He also supports the KARUNA social cooperative in Berlin as a sponsor. In 2022, the actor can be seen in the feature film Die Känguru-Chroniken II as well as in the ZDFneo series Ich dich auch! and Löwenzahn in.