Norwegian Ninja (Norwegian: Kommandør Treholt & ninjatroppen) is a 2010 Norwegian action comedy film, directed by Thomas Cappelen Malling. The film, based on a 2006 book, presents real-life espionage-convicted Arne Treholt as the leader of a ninja group saving Norway during the Cold War and stars Mads Ousdal as Treholt.

The film is loosely based on the story of Norwegian politician and diplomat Arne Treholt, who in 1985 was convicted of high treason and espionage on behalf of the Soviet Union and Iraq. In 2006, Thomas Cappelen Malling wrote the book Ninjateknikk II. Usynlighet i strid 1978 ("Ninja Technique II: Invisibility in combat 1978"). The book was presented as a military manual written by Treholt in 1978. It achieved a certain cult status, and was considered a success at 5,000 units sold.