Leon Seidel was born in Cologne on November 22 1996. Following his screen debut in the 2009 feature release "Berlin 36", he became popular with his leading turn in the children's film "Teufelskicker" ("Devil's Kickers", 2010). After a supporting role in "Wintertochter" ("Winter Daughter"), he played the character of Huck Finn in the 2012 screen adaptation of "Tom Sawyer".

In 2014, Seidel appeared in the TV comedy "Nachbarn süß-sauer" before getting rave reviews for his performance in the TV drama "Die Auserwählten", which also garnered him a nomination as Best Supporting Actor at the Deutsche Schauspielerpreis.

Seidel went on to guest-star on several TV shows and then returned to the big screen as one of the leads in the WWII drama "Unter dem Sand - Das Versprechen der Freiheit" ("Land of Mine", DK/DE 2015), which was released in April 2016. Shortly afterwards, he was seen opposite Jannis Niewöhner, Julia Koschitz and André M. Hennicke in "Jonathan".