American Ninja Warrior (sometimes abbreviated as ANW) is an American sports entertainment reality show based on the Japanese television reality show Sasuke, which also serves as a successor of American Ninja Challenge. It features a set of obstacle courses in various cities, which competitors attempt to conquer. The obstacle courses are divided into Qualifiers courses, Semifinals courses, and a four-part Finals course which is based at Las Vegas Strip (sometimes called Mount Midoriyama). The competitor who finishes all the courses in the fastest time wins a cash prize of $1,000,000. Starting with season 10, if one remaining competitor fails on any of Finals course parts but has completed it more than the others in the fastest time, they win a consolatory $100,000 prize. The show is hosted by Matt Iseman (the show's ) and Akbar Gbaja-Biamila. To date, only three competitors have won the main cash prize: Isaac Caldiero, Drew Drechsel, and Vance Walker (who is the only competitor to do it twice). Furthermore, Geoff Britten, Daniel Gil, and Caleb Bergstrom are the only three runners-up who have achieved Total Victory.

The series premiered on December 12, 2009, on cable channel G4. For the first three seasons, the show only screened a single qualifying and semifinals course while the top contestants travelled to Japan to compete at the Sasuke seasons' finals course. In 2012, the modern format began with multiple qualifying and semifinals courses in several cities, a fixed Finals course in Las Vegas, and now regularly airing on NBC. In 2020, following COVID-19 restrictions, the show abolished the usual format and filmed a shorter season in St. Louis studio with no live audience. Production for the 13th season reverted to the previous format, although with fewer filming locations.

On April 20, 2025, it was announced that American Ninja Warrior had been renewed for a seventeenth season, and will premiere on June 2, 2025.