Diego Velazquez (actor) as Billy Thunderman, an energetic (and dimwitted) younger eleven-year-old brother to Phoebe, Max, and older brother to Nora.
Diego Velazquez (actor) as Billy Thunderman, the 3rd born thunderman child. He is an energetic (and dimwitted) eleven-year-old little brother to Phoebe, and Max, and older brother to Nora.