David F. Wnendt was born in 1977 in Gelsenkirchen as the son of a diplomat and grew up in Islamabad, Miami, Brussels and the German town Meckenheim. He made his first forays into the world of theater and film production working in a variety of jobs, such as lighting technician, editor and production assistant. He graduated in Business Administration and Journalism from Berlin Free University and completed a one-year film course at the Film and TV School of the Academy of Performing Arts in Prague. Then he was accepted at the renowned Hochschule für Film und Fernsehen "Konrad Wolf" in Potsdam-Babelsberg in 2004. While still a student of the university's Directing program, he won an award at the International Short Film Festival interfilm Berlin in 2006 for his short film "California Dreams".

Wnendt's first medium-length feature film "Small Lights" starring Rosalie Thomass was broadcast on ARTE in 2008. Then Wnendt's powerful graduation film, "Kriegerin" ("Combat Girls"), which he both wrote and directed, was met with great acclaim: the drama, depicting the right-wing scene in eastern Germany, won three German Film Awards shortly after its cinema release in 2012: in Bronze for Best Feature Film, Best Screenplay and Best Actress for Alina Levshin. Wnendt also received the Bavarian Film Award for Best Young Director, the Young German Cinema Award, the Prix Genève-Europe for Best Screenplay and the First Steps Award for Best Full-Length Feature Film.

Wnendt's next film featured another extraordinary female protagonist: "Feuchtgebiete" ("Wetlands", 2013), based on the best-selling novel by Charlotte Roche, tells the story of a young woman (Carla Juri) who takes a unconventional stance towards body hygiene and who desperately wants to reunite her divorced parents. The film was a remarkable box office success.

David Wnendt made another film adaptation of a bestseller with the satire about the return of Adolf Hitler in modern Berlin: "Er ist wieder da" ("Look Who's Back") opened to great acclaim in German cinemas in October 2015 and received five nominations at the 2016 German Film Awards, including Best Feature Film and Best Director.   

Wnendt was then supposed to film Wolfgang Herrndorf's bestseller "Tschick," but was replaced as director by Fatih Akin in July 2015. He directed the TV movie "Borowski und das dunkle Netz" (2017) from the popular "Tatort" series, which received mixed reviews.  

In spring 2018, Wnendt directed "The Sunlit Night," about a young artist who, after breaking up with her boyfriend, moves from New York to Norway, where she is confronted with a completely different  way of life. The film premiered at the Sundance Film Festival (USA) in January 2019. The German release was in fall 2021.