Cassian Cary Elwes (born 7 August 1959) is a British independent film producer and talent agent.

Cassian Elwes began his producing career with 1984's Oxford Blues starring Rob Lowe and Ally Sheedy; he has continued enjoying success in film.

In 1989 he produced the independent film Never on Tuesday which featured a cast of cameos including Charlie Sheen, Emilio Estevez, Judd Nelson, Nicolas Cage, and Cary Elwes.

Elwes has been involved in arranging financing and distribution for 23 films including Lawless, directed by John Hillcoat, (The Road), starring Shia LaBeouf and Tom Hardy, and the thriller The Paperboy, directed by Lee Daniels (Precious), starring Matthew McConaughey and Zac Efron.

Elwes produced the period drama The Butler, which was directed by Lee Daniels and featured an ensemble cast, including Forest Whitaker, Oprah Winfrey, John Cusack, Jane Fonda, Terrence Howard, Vanessa Redgrave, Alan Rickman, Liev Schreiber, and Robin Williams among others.