Geoffrey Barkas (born Geoffrey de Gruchy Barkas, 27 August 1896 – 3 September 1979) was an English filmmaker active between the World War I and World War II. Barkas led the British Middle East Command Camouflage Directorate in the Second World War. His largest "film set" was Operation Bertram, the army-scale deception for the battle of El Alamein in October 1942.

Barkas was born in 1896 in Richmond, Surrey where his father was a librarian, to parents from Jersey families. His father was Albert Atkin Barkas (born 1861) and his mother was Anna Julia de Gruchy (born 1863); both were from St. Helier.

In the First World War, he served in the 1915 Gallipoli campaign at Suvla Bay, and then in the later part of the Battle of the Somme in France, where he won a Military Cross.

Between the wars, Barkas worked on silent films and then feature films, starting as a writer and producer, and then directing his own films such as The Manitou Trail and The Lumberjack (1925) and The Third Gun (1929), the latter being a three-reel short filmed in the Phonofilm sound-on-film process. He co-directed with Michael Barringer (Blockade, Q-ships, The Infamous Lady), Anthony Asquith (Tell England), Berthold Viertel (Rhodes of Africa) and Milton Rosmer (The Great Barrier), he also edited Red Ensign directed by Michael Powell. Work became increasingly difficult to find in the economic depression of the 1930s, and after directing the critically acclaimed African exteriors for Robert Stevenson's King Solomon's Mines in 1937, it dried up altogether.

In 1927 he married scriptwriter Natalie Webb (1899–1979) in Wycombe, Buckinghamshire. She wrote an account in 1934 of the production of Barkas' film Palaver.

Having found life hard in the film industry during the depression in 1937, Barkas joined Shell-Mex/BP under Jack Beddington, who guided Barkas into military camouflage. In May 1940, he was rapidly drafted into the Royal Engineers with a summary 10-day basic training course, followed by a camouflage course at the Royal Artillery camp at Larkhill, where modern concerns such as hiding from aerial and infrared photography were taught alongside traditional techniques.

He began in Northern Ireland in 1940, teaching army drivers how to camouflage their vehicles. He found that they regarded their camouflage nets as "cloak[s] of invisibility", and in consequence would park trucks out in the open, covered by nets not "garnished" with the provided strips of canvas or hessian. His response was to print a training pamphlet, designed to be entertaining as well as instructive. It contained "an instructional poem" called The Sad Story of George Nathaniel Glover. Glover was a driver who "never, never could be made/ To Park his Lorry in The Shade" and who uses a net "Which he had thrown across the bonnet, With not a stitch of garnish on it." The result is that a bomb falls exactly on target, and when his friends come to find him "Not One Trace did they discover/ Of Driver George Nathaniel Glover". The army allowed the pamphlet to be published, and it became popular enough to spread from Northern Ireland across all British Army commands.

Barkas's next step was to run popular demonstrations of camouflage. He would assemble about 60 trucks, coaches and smaller vehicles and discuss with the non-commissioned officers how to hide these from the air. They would agree that a line of trucks could be parked by a hedge and all together draped with nets to appear as a thick belt of vegetation, or arrange a vehicle as a pitched-roof outhouse to a building. Then the commanders would arrive, and Barkas would give a speech about camouflage methods to defeat aerial reconnaissance. He would then signal the start, the unit would hide all its vehicles, and a moment later, using his film-making skill with timing, an aircraft would arrive and start observing. It rarely found more than a few of the vehicles.