Lea van Acken, who was born in 1999, made her acting debut in small role at the 2011 open-air staging of "Winnetou - Der Ölprinz" at the Karl-May-Festival in Bad Segeberg. Two years later, she auditioned for Dietrich Brüggemann's feature film "Kreuzweg", and was eventually cast in the leading role. In the film, she portrays a 14-year-old girl who is brought up in a family which follows the religious teachings of an ultra-conservative Catholic group. Impressed by her memorable performance in "Kreuzweg", director Hans Steinbichler cast her as the lead in "Das Tagebuch der Anne Frank" ("The Diary of Anne Frank"), which opened in cinemas March 2016. For this performance she won Best Young Actress at the Bavarian Film Awards.

In 2016, Lea van Acken played an important supporting role in the love drama "Sag mir nichts" (TV) and also featured in a bit part in the TV crime film "Spreewaldkrimi: Spiel mit dem Tod" which premiered at the Festival des deutschen Films in Ludwigshafen. In the children's film "Bibi & Tina: Tohuwabohu Total" (2017) directed by Detlev Buck, she played an Albanian girl who is threatened by forced marriage and looks for help with Bibi and Tina. In the children's and youth film "Ostwind - Aufbruch nach Ora" ("Windstorm - And The Wild Horses", 2017) she played the uppity daughter of an Andalusian hacienda owner.