William Eubank (born November 15, 1982) is an American film director, screenwriter and cinematographer. On his first feature film, Love, released in 2011, in addition to directorial and director of photography duties, Eubank also served as production designer. His second feature film, The Signal, premiered at the 2014 Sundance Film Festival and was released in theaters by Focus Features on June 13, 2014. His third feature film, the science-fiction horror film Underwater, was released in January 2020 by 20th Century Fox.

Eubank was born on November 15, 1982, in Holyoke, Massachusetts. His father, Carlyle Eubank II, is a fine art consultant, former Christie's representative, and adviser to the Office of Fine Arts at the State Department. His mother, Patricia Reeder Eubank, is a children's book author and illustrator. The second of four siblings, Eubank has one older sister and two younger brothers, and grew up in the Santa Ynez Valley, a noted wine-producing region north of Los Angeles.

Growing up he was inspired by his grandfather, a former US Navy cinematographer; from the stories he would tell – one involved operating a camera while flying underneath the Golden Gate Bridge – Eubank decided he wanted to either attend the United States Naval Academy or become a cinematographer, eventually settling on the latter. Eubank grew up involved in Scouting and, like filmmakers Steven Spielberg and David Lynch, is an Eagle Scout.

When Eubank was young, he had an interesting experience with the verisimilitude of cinema. At the time that he first watched the 1974 film Chinatown, set in the year 1937, Eubank was unaware that it was a period piece, assuming it to have been made contemporaneously in 1937. When he found out it had been made almost four decades after the era it depicted, Eubank came to a realization about film's power.

Eubank began accepting jobs as a director or cinematographer at age 18. A number of Eubank's early works featured the use of in-camera speed 'ramping'. As a cinematographer and camera operator, Eubank was hired by the UFC to film fights in this style. Eubank was never hired to direct commercials, but did release specs, as well as reels and camera tests. Eubank was accepted into UCLA where he took cosmology classes that he would later cite as an influence on his films' ideas. After attending UCLA for two years, he had not made it into the film program, and, impatient, he dropped out and went to work at Panavision Woodland Hills as a camera repair technician and digital imaging technician.

Eubank would become a seasoned Panavision employee, staying at the company for the next eight years. Eubank attended the Sundance Film Festival five times representing Panavision, dreaming of attending as a director. He would meet with his Navy cinematographer grandfather, who lived in Salt Lake City, who insisted Eubank would someday attend with a film.

While at Sundance and elsewhere, it was Eubank's job to promote and provide support for the Panavised CineAlta F900, which had singularly moved Hollywood into the digital cinema era with its use in the production of George Lucas's 2002 film Star Wars: Episode II – Attack of the Clones, the third, and first major, feature film to be released that was shot entirely on a 24p digital camera. Using his position at Panavision, Eubank convinced the Australian cinema product manufacturer Blackmagic Design to send him an early edition of an SDI capture card. Using this early card and the brand-new eSATA drives that had just appeared on the market, Eubank stacked 14 hard drives on top of each other and drilled a hole into a Power Mac G4 in order to create an NLE system on a personal computer that could directly capture the F900's Full HD 1080p footage. When the working result was seen at Panavision, co-workers agreed a shift was about to occur in the industry.

After working at Panavision for some time, Eubank was occasionally given permission to borrow cameras and lenses for his tests. When Panavision eventually tabulated what he had used, they realized he had been given the loan of what would have been multiple million dollars' worth of rental fees. Eubank describes his time at Panavision as serving as his film school. Sent to sets of films like Collateral and Superman Returns, Eubank would take a notebook and draw diagrams of where the gaffer had placed all the lights and would then go see the film when it came out and compare the on-screen results to his journals. Eubank credits Panavision's kindness to him as being essential: "I owe my entire career to those guys".