Kotti Yun was born in Trier, Germany in 1983 and grew up bilingually in Berlin, Bremen and Seoul. From 2008 to 2012, she studied drama at the Korea National University of Arts in Seoul and then at the Ernst Busch School of Drama in Berlin, where she graduated with a diploma. From 2014 to 2016 she was a member of the ensemble of the Chemnitz Theatre / Figurentheater. From 2015, she took on roles at various theatres, including Deutsches Theater Berlin and Schauspiel Köln. In 2016, Kotti Yun was awarded the Grünschnabel Prize at the Figura Theatre Festival in Baden, Switzerland for her one-woman show "Flying Dogs".

Since the beginning of the 2010s, she has appeared in TV and film productions such as "Weak Heart Drop" (2011) by Alex Ross and in series such as "Großstadtrevier" (2015), "Sibel und Max" (2016), "Die Heiland" (2020) and "Oh Hell" (2021). She played a supporting role in Nicolette Krebitz's acclaimed drama "Wild" (2015) and also appeared in Tim Fehlbaum's award-winning post-apocalyptic thriller "Tides" (2020).

Kotti Yun played one of the two lead roles alongside Lena Urzendowsky in Michael Klier's "Zwischen uns der Fluss" ("L'être humain", 2022). In this drama about an unusual friendship, in which Yun portrays a young woman traumatised by a racist attack, both leading actresses were involved in the script.

Following this, she took on further roles in TV series such as "Notruf Hafenkante", "Letzte Spur Berlin", "Theresa Wolff" and "Nord bei Nordwest" (all 2022/2023).