Kanan's first notable role was that of villain Mike Barnes in the 1989 film The Karate Kid Part III directed by Academy Award winning Director, John Avildsen. Kanan reprised his role as Mike Barnes from The Karate Kid III for the fifth season of Cobra Kai. Sean is also a writer with books out including The Modern Gentleman; Cooking and Entertaining with Sean Kanan, Success Factor X with co author Jill Liberman and in 2021 Sean wrote Way of the COBRA in which he, as Sensei, inspires and instructs students on techniques to define their most authentic and successful self. The acronym COBRA stands for character, optimization, balance, respect, and abundance. He shares some of his own experiences from landing the breakout role of Mike Barnes in the Karate Kid III, to how he almost lost the role and his life in the process. In 2024, Kanan co-authored the third book in the WOTC series titled Way of the COBRA Couples, with his wife Michele Kanan.