Timm Kröger was born on November 17th 1985 in Itzehoe, Germany. After graduating from high school in 2005, he worked for over nine months as a photographer accompanying a traveling circus through Germany. After that he started his studies at the European Film College (EFC) in Ebeltoft, Denmark. After graduation, he stayed at the EFC for another year as a teaching assistant and later completed an internship at ARRI Rental in Munich.

In 2008, Timm began a second course of study at the Filmakademie Baden-Württemberg, initially focusing on cinematography and later switching to the documentary directing department. He made his directorial debut at the Filmakademie with the 27-minute documentary "Sheriff - Vom Schweinehirten zum Superstar" (2010), which followed a former pop singer in a cowboy outfit and was screened at the DOK Leipzig festival. The following year, he created "Das leicht beunruhigende Schaukeln bei der Fahrt ins Tal," an essayistic documentary about the summer of 2011 between the Alpine plateau and the North Sea. Kröger also worked as a cinematographer on films by his fellow Film Academy students.

Despite specializing in documentary filmmaking, Kröger's final project was a feature-length fiction film titled "Zerrumpelt Herz" ("The Council of Birds", 2014). It was about three friends who tried to visit a reclusive young composer living in the woods, but found his cabin abandoned. The film premiered at the 2014 Venice Film Festival in the independent section Settimana Internazionale della Critica (Critics' Week), where it received mostly positive reviews. It went on to screen at numerous other festivals and was nominated for the First Steps Awards in the feature film category.

In the following years, Kröger worked on films by other directors, as editor on Lena Leonhardt's award-winning documentary "Hundesoldaten" (2016) and as cinematographer on Sandra Wollner's feature films "Das unmögliche Bild" ("The Impossible Picture", DE/AT 2016) and "The Trouble With Being Born" (AT/DE 2020, also as co-producer).

The black and white film "Die Theorie von Allem" ("The Theory of Everything", DE/AT/CH 2023) was Timm Kröger's second feature film as writer (in collaboration with Roderick Warich) and director. Set in 1962, the mystery-thriller revolves around a physicists' congress in the Swiss Alps that is marred by strange occurrences. The film was invited to the Venice Film Festival and won the Gilde Film Prize for Best Film (National) at the Leipzig Film Festival in 2023. It also won the José Luis Guarner Critics' Prize for Best Film at the Sitges Film Festival. The German theatrical release took place in October 2023.