Daniel Andreas Sager was born in East Berlin in 1985 and grew up in Moscow. After graduating from high school, he first studied social anthropology and philosophy in Leipzig. In the Leipzig art house cinema "Prager Frühling" he directed the short film festival "Junges Kino" (Young Cinema), which was intended to provide a forum for the work of up-and-coming filmmakers. Finally, he began studying directing at the Filmakademie Baden-Württemberg, where he graduated in 2015. During his studies, he received a Baden-Württemberg state scholarship that enabled him to study for a year at the UCINE Film School in Buenos Aires, Argentina. His 45-minute documentary "Licht und Schatten" ("Light and Shadow") about three losers of the reunification in East Germany, screened at several international festivals.  

Sager made his feature film debut in 2015 with his graduation film "The Long Distance." The documentary follows a German athlete manager who brings two runners from Africa to Germany so they can compete in races. The film premiered at the 2015 Zurich Film Festival; it won the No Fear Award at the First Steps Awards. It was first broadcast on German TV in late 2015.  

After graduating, Sager began working as a freelance writer, director, journalist and cinematographer. For television, he realized documentaries (e.g. "Runner's High", 2016; "Deutschland auf Koks", 2021), reportages (e.g. "Mexico - Dem Ziel so Nah," 2019; "Across the Sahara," 2021) and magazine features (for example for "Frontal 21").   

At the Munich DOK.fest 2021, Daniel Andreas Sager presented his cinema documentary "Hinter den Schlagzeilen" ("Behind the Headlines"). In it, he accompanies investigative journalists who are researching the so-called "Ibiza Affair" surrounding Austrian Vice Chancellor Heinz-Christian Strache. The film was released in fall 2021.