No casting has been announced yet for the movie.
"Button Man tells the story of ex-military contractor Harry Exton," a press release for the streaming service said. "The first true hero of the post-truth age, Harry's a proxy in a clandestine competition among the super rich. Paid to fight to the death in modern-day gladiatorial contests, Harry sets out on a relentless journey to use these twisted elites' own dark machine to bring their corrupt world crashing down."
Helgeland's credits include L.A. Confidential, A Knight's Tale, Mystic River, 42 and Legend. He also is writing one of four planned Game of Thrones spin-offs.
Netflix's roster of original movies includes the Ben Affleck-Charlie Hunnam action-adventure thriller Triple Frontier, as well as the Oscar-winning, Spanish-language family drama Roma and the horror flick Bird Box.