Kai-Michael Müller was born in Berlin on July 9 1991. At the age of ten, he made his screen debut in the children's film "4 Freunde und 4 Pfoten" (2001-2003) alongside his younger sister Nicole Mercedes. He next was one of the leads in "Der Fluch des schwarzen Schwans" ("The Curse of the Black Swans", 2002) and played a supporting role in the award-winning drama "Sugar Orange" (2004).

He went on to appear in the theatrical releases "Max und Moritz Reloaded", "Knallhart" ("Tough Enough", 2006) and "Gangs" (2009), and in TV productions like "Sperling und die kalte Angst" (2007) and the miniseries "Im Angesicht des Verbrechens" ("In Face of the Crime", 2010). In 2011, he starred opposite Lukas Steltner in the improvised feature film "Stadt Land Fluss". Following turns in the award-winning drama "Am Himmel der Tag" ("Breaking Horizons", 2012) and in "Nemez" (2012), Müller guest-starred in an episode of the TV series "Verbrechen nach Ferdinand von Schirach" (2013, TV).

Kai-Michael Müller next became the male lead in the arthouse horror film "True Love Ways", which premiered at the 2014 Hofer Filmtage, and was released theatrically in October 2015.