Schilling's screen acting debut was in 1996, when he appeared in the Sat.1 TV series Hallo, Onkel Doc!

He was later cast in the theatrical film Paradise Mall [de] (1999) where he played alongside Franka Potente, Daniel Brühl and Heiner Lauterbach, but the breakthrough for him came with his performance in Crazy (2000, directed by Hans-Christian Schmid), for which he received the Talented Young Actor Award of the Bayerischer Filmpreis.

In the critically well-received 2004 film Before the Fall (German title: Napola – Elite für den Führer, directed by Dennis Gansel) Schilling appeared alongside Max Riemelt as a young and fragile student at a Nazi elite school (Napola).

Schilling was later given the role of the young Adolf Hitler in Urs Odermatt's 2009 film Mein Kampf (the UK DVD release is marketed as Dawn of Evil: Rise of the Reich [de]), co-starring Götz George.

In a 2008 interview he said he was not much of an extrovert, and that to him having to deliver oneself up on a day-to-day basis was a major disadvantage of being in the acting profession.