Sia Joins Cast of My Little Pony Movie Sara Alessi July 25, 2016 Top Stories SANTA MONICA/PAWTUCKET: Singer-songwriter Sia has come on board the cast of My Little Pony: The Movie, due out in theaters next year. The content you are trying to access is only available to members. Log In Register Allspark Pictures Hasbro Lionsgate My Little Pony: The Movie Sia 2016-07-25 Sara Alessi Share