John Mollo (18 March 1931 – 25 October 2017) was a British costume designer and writer on the history of the military uniform. He created the costumes for the first two installments of the Star Wars original film trilogy. Mollo was nominated for the Academy Award for Best Costume Design twice, for Star Wars (1977) and Gandhi (1982), winning both times.

Mollo was born in London on 18 March 1931. His father was Eugene Simonovitch Mollo, a Russian immigrant who had escaped Russia in the 1920s, and his mother was Ella Clara Mollo (née Cockell). Eugene Mollo had started his own company that specialised in spraying cement. He was a collector of tin soldiers and military insignia and he wrote a book, Russian Military Swords, 1801–1917. Eugene was also a noted illustrator, and some of his drawings are now held in the Victoria and Albert Museum in London. John Mollo followed his father's interest in military history and developed a particular interest in military uniforms from a very young age. He recalled being especially inspired when he saw the 1935 film Clive of India as a child and returned home from the cinema to draw the costume of King George II. John Mollo was educated at Charterhouse School and then went on to study at the Farnham School of Art in Surrey. After World War II, he was conscripted to do his national service in the King's Shropshire Light Infantry in Hong Kong.

Mollo subsequently moved into costume design. For his first film, Mollo unexpectedly found himself working not on a historical military drama but in a genre he had no knowledge of: science fiction. He was commissioned in 1975 by a young filmmaker named George Lucas to devise uniforms and outfits for a fantasy space war film, Star Wars. When asked at the time by a friend about the project, Mollo said that he thought it was a "sort of a space western and one of the heroes is a dustbin". Lucas's project envisioned a cast of heroes battling an evil Galactic Empire, and he briefed Mollo to design costumes that would not resemble the stereotypical "spacey" look of earlier science fiction productions such as Flash Gordon — " I don't want the audience to notice any of the costumes. I just want to see light versus dark." The aim was to make Lucas's fantasy universe appear authentic – Mollo considered that his total ignorance of science fiction was advantageous in achieving this. Lucas provided Mollo with sketches and concept art by Ralph McQuarrie to work from, working McQuarrie's designs for Imperial stormtroopers and the malevolent character of Darth Vader into functional costumes for actors to wear. McQuarrie's image of Darth Vader had developed from Samurai armour, and Mollo built up a costume using a combination of clerical robes, a motorcycle suit, a German military helmet and a gas mask from Bermans and Nathans costumiers in Camden Town. Mollo intentionally designed the uniforms of Imperial officers to resemble German Nazi officers' uniforms; by contrast, the heroes of the film were dressed in costumes resembling Wild West outfits. Mollo was surprised by the success of Star Wars, and in 1978 he won an Academy Award for Costume Design. In his acceptance speech at the Oscars ceremony, he said that the Star Wars costumes were "really not so much costumes as a bit of plumbing and general automobile engineering.

He died on 25 October 2017, aged 86