Mafia vs. Ninja also known as Hongmen jue e zhe (simplified Chinese: 洪门小子; traditional Chinese: 洪門小子; pinyin: Hóngmén xiǎozi; lit. 'Mafia boys or The Organization's boys')

is a 1984 martial arts film directed by Robert Tai. Made in Hong Kong, it stars Alexander Lou, alongside Charlema Hsu, Silvio Azzolini and Eugene Thomas. The film was originally released as a mini-series of several episodes which was later edited to create the theatrical version. Both versions follow the basic storyline structure, although the mini-series provides richer detail and background for the main characters and the antagonists.

The film remains relatively obscure to the general public, although over the years it has gained a large cult following among martial arts cinema enthusiasts.