David Harold Yost (born January 7, 1969) is an American actor and producer. He is best known for portraying Billy Cranston in Mighty Morphin Power Rangers, Mighty Morphin Power Rangers: The Movie, Mighty Morphin Alien Rangers and Power Rangers Zeo.
Yost was born in Council Bluffs, Iowa. He moved around the United States while winning many national gymnastics competitions, most notably the state championships in Iowa and Montana. In 1987, he graduated from Amador Valley High School in Pleasanton, California. In 1991, he graduated from Graceland University in Lamoni, Iowa with a Bachelor of Arts in communication and dramatic arts.
Yost moved to California with hopes of becoming an actor, and won the part of Billy Cranston (Blue Power Ranger) in the television series Mighty Morphin Power Rangers three months after arriving. He starred in almost 200 episodes of the show's first four seasons. He was the only cast member to appear in every single episode of the original series; his character never changed his colors or passed on his power coins to successors like the rest of the original cast. Yost's most high-profile work was his appearance in Mighty Morphin Power Rangers: The Movie (1995), which took in over $60 million at the box office. The film served as a non-canonical alternate opening for the third season.