Sebastian David Fitzek (born 13 October 1971 in West Berlin) is a German writer and journalist.

Die Therapie), was a bestseller in Germany in 2006, toppling The Da Vinci Code from the first position.

After High school in Charlottenburger Wald-Gymnasium, Fitzek started studying veterinary, but stopped after 3 months.

He attended law school until the first state examination, earned his doctorate degree in copyright and worked then as editor-in-chief and program director for different radio stations in Germany.

After 13 cancellations from different editors, he finally released his book in July, 2006 under Droemer Knaur Verlag.

The Odeon Film AG bought the movie rights for Therapy and it was subsequently turned into a TV series in 2023.

and his first children's book called Pupsi & Stinki together with illustrator Jörn Stollmann.

In November, 2020 The Package was published in English by Head of Zeus, translated by Jamie Bulloch.