The Polka King is a 2017 American biographical comedy film directed by Maya Forbes and written by Forbes and Wallace Wolodarsky. The film is about real-life Polish-American polka band leader Jan Lewan, who was imprisoned in 2004 for running a Ponzi scheme. The film stars Jack Black as Lewan, as well as Jenny Slate, Jason Schwartzman, and Jacki Weaver. It premiered at the 2017 Sundance Film Festival on January 22, 2017. It was released on Netflix on January 12, 2018.

Jan Lewandowski known professionally as Jan Lewan, is a Polish-American songwriter and polka band leader. The Grammy Award-nominated musician was convicted of fraud charges in 2004, for financial crimes described by The Morning Call as a "classic Ponzi scheme".