Billy Cranston is a fictional character in the Power Rangers universe. He is the Blue Ranger (triceratops) in the series Mighty Morphin Power Rangers, and was portrayed by actor David Yost. Billy is the only original Power Ranger to remain for the entire MMPR series, and is the second longest-serving Ranger overall behind Tommy Oliver. Until his departure, he is considered the brains of the Power Rangers team, creating many gadgets with which to solve problems that not even Zordon foresees, and he even invents the first team's wrist-worn communication devices. A reimagined version of Billy appears in 2017 reboot film, played by actor RJ Cyler.

Power Rangers is a 2017 American superhero film based on the franchise of the same name. It was directed by Dean Israelite from a screenplay by John Gatins and a story conceived by the writing teams of Matt Sazama and Burk Sharpless, and Michele and Kieran Mulroney. It is the third installment in the Power Rangers film series, and is a reboot that loosely adapts "Day of the Dumpster", the pilot episode of Mighty Morphin Power Rangers. The film features the main characters of the television series with a new cast, starring Dacre Montgomery, Naomi Scott, RJ Cyler, Becky G, Ludi Lin, Bill Hader, Bryan Cranston, and Elizabeth Banks. The film follows a group of teenagers who gain newfound powers, and must use them to protect Earth from an ancient reawakened threat. Franchise creator Haim Saban returned to produce the film under his investment firm.