William Peltz (born May 30, 1986)^[2] is an American actor, who is best known for his roles in Unfriended, Manifest and Men, Women & Children.

Peltz was born in New York City,^[2] the son of Nelson Peltz, a billionaire businessman. Peltz's father is of Austrian Jewish and Russian Jewish descent, while his mother has German, Welsh, and English ancestry.^[3][4] Peltz celebrated his Bar Mitzvah.^[5] Among his siblings are actress Nicola Peltz and former ice hockey defenceman Brad Peltz. He has seven siblings, and two half-siblings from his father's previous marriages.^[3][6]

Peltz played hockey in his youth, advancing to Tier III Junior hockey with the New Jersey Hitmen.^[7]

Peltz became interested in acting while reading scripts with his sister Nicola.^[2][8] In 2009, he moved to Los Angeles and secured his first roles in film productions.^[8] In 2014, he had his first major role in Jason Reitman's drama Men, Women & Children. That same year, he starred in the horror film Unfriended as Adam Sewell.

He and his sister actress Nicola Peltz have matching Hebrew tattoos on their ribs, that read: "family".^[9]

He has been in a relationship with American fashion model Kenya Kinski-Jones since 2011.