Amell is just one of nine celebrities competing in the event. Also competing are Erika Christensen (Parenthood), Derek Hough (Dancing With the Stars, World of Dance), Natalie Morales (Today), two-time Olympic gold medalist Ashton Eaton, comedian Nikki Glaser, former Yankee Nick Swisher, comedian Jeff Dye and Mena Suvari (American Beauty).
Each celebrity will be paired with an "elite ninja." The pairings are Kevin Bull/Eaton, Kacy Catanzaro/Amell, Drew Drechsel/Swisher, Natalie Duran/Suvari, Daniel Gil/Hough, Jessie Graff/Glaser), Grant McCartney/Morales, Meagan Martin/Dye and Flip Rodriguez/Christensen.
Amell confirmed the news on his own Twitter feed.
Celebrity American Ninja Warrior will be part of NBC's charitable programming for the third annual Red Nose Day, which raises money for children living in poverty.
American Ninja Warrior celebrity edition airs Thursday, May 25 at 8 p.m. ET on NBC.
American Ninja Warrior is a spin-off of the Japanese sports entertainment show Sasuke, which airs internationally as Ninja Warrior. Competitors attempt to make their way through a series of increasingly complex and difficult obstacle courses culminating a final competition in Las Vegas for the right to become an American Ninja Warrior.
After a violent shipwreck, billionaire playboy Oliver Queen (Stephen Amell) was missing and presumed dead for five years before being discovered alive on a remote island in the North China Sea. Oliver returned home to Star City, bent on righting the wrongs of his family and fighting injustice. As the Green Arrow, he protects his city with the help of former soldier John Diggle (David Ramsey), computer science expert Felicity Smoak (Emily Bett Rickards), his vigilante-trained sister Thea Queen (Willa Holland), former police captain Quentin Lance (Paul Blackthorne) and brilliant inventor Curtis Holt (Echo Kellum).
Newly appointed Mayor Oliver Queen finds himself challenged as he fights on two fronts for the future of Star City. With Diggle back in the military and Thea adamant about hanging up her hood as Speedy, Team Green Arrow is down to just Oliver and Felicity – but they're no longer the only vigilantes in town. Green Arrow's public defeat of Damien Darhk at the end of Season Four has inspired a new crop of masked heroes to step up and defend the city, though their painful inexperience makes them obstacles, rather than allies, in the field. The arrival of a deadly new adversary will force Oliver to confront questions about his own legacy, both as mayor and as the Green Arrow.
Based on the characters from DC, ARROW is from Bonanza Productions Inc. in association with Berlanti Productions and Warner Bros. Television, with executive producers Greg Berlanti ("The Flash," "Supergirl"), Marc Guggenheim ("Eli Stone," "Percy Jackson: Sea of Monsters"), Andrew Kreisberg ("The Flash," "Supergirl"), Wendy Mericle ("Desperate Housewives," "Eli Stone") and Sarah Schechter ("Supergirl," "Blindspot").