Sebastian Ko, born in Walsrode in 1971, studied theater, film and television in Cologne. After earning his master's degree in 1997, he gained practical experience by taking on various jobs on film productions, from driver to assistant director. Soon he made his first own short films and worked as an assistant director on WDR radio play productions. In 1999 Ko began his second degree, this time in directing at the Film University Babelsberg Konrad Wolf. Over the next few years, he made several short films that were screened at international festivals. His short film "Ladybug" (2006) was screened in competition at the Max-Ophüls-Preis film festival in January 2006. Ko graduated with the medium-length film "Schonzeit". 

In 2008, Sebastian Ko began working as a film critic for WDR 1Live and other radio stations. In early summer 2014, he realized a radio play for WDR based on his own idea; he wrote the draft together with Marcus Seibert. Briefly before that, in February/March 2014, the shooting of Ko's first feature-length film had taken place: the family drama "Wir Monster" ("We Monsters"), which he penned together with Marcus Seibert, tells the story of two parents who want to cover up an alleged crime committed by their teenage daughter at any cost. The premiere took place in competition at the 2015 Max Ophüls Prize Film Festival.  

In the following years, Ko directed four crime thrillers of the popular and long-running crime series "Tatort": "Kartenhaus" (2016), "Wacht am Rhein" (2016), "Mitgehangen" (2018) and "Weiter, immer weiter" (2019). He also directed episodes of the crime series "Alarm für Cobra 11 - Die Autobahnpolizei" (2017) and "Helen Dorn" (2019, 2020), as well as the TV thriller "Kein einfacher Mord" (2020). With "Heile Welt" (2021), he directed another feature-length episode of the "Tatort" series, followed by the crime thriller "Ostfriesensühne" (2022, TV). 

In parallel with his TV work, Ko began work in 2019 on the feature film "Geborgtes Weiß" ("Borrowed White"), a psychodrama about guilt and repression.  The film premiered at the Festival of German Film in Ludwigshafen in 2021 and opened regularly in theaters in July 2022.