This forthright and witty character from the Illawarra won Academy Awards for the Gene Kelly musicals An American in Paris (1951), Les Girls (1957) and the 1959 Marilyn Monroe-Tony Curtis comedy Some Like It Hot.

Among the 300-plus movies he worked on from the 1930s to the 1960s were such classics as Casablanca, The Maltese Falcon, Oklahoma!, Harvey, Arsenic and Old Lace, 42nd Street and Gypsy, the latter earning him a fourth Oscar nomination in 1963.

In Los Angeles, Orry-Kelly ran with the likes of Cole Porter, Errol Flynn and gossip columnists Hedda Hopper and Louella Parsons. When he died in 1964, his pallbearers included Cary Grant, Tony Curtis and directors Billy Wilder and George Cukor. The president of Warner Bros, Jack Warner, described him as a "warm and wonderful person" with "a talent for living".

Yet Orry-Kelly, who was born Orry George Kelly in 1897, is largely unknown in Australia. Director Gillian Armstrong had never heard of him when producer Damien Parer suggested they collaborate on a documentary.

"I thought, 'Who's Orry-Kelly?' Armstrong says.

"Then I saw the list of all the films and I was like, 'What? Casablanca? 42nd Street? An Australian designed these films?' I felt people should know about him."

Armstrong's documentary, Women He's Undressed, will have its world premiere on a cruise ship during the Sydney Film Festival on June 10 before a cinema release on July 16. And with Random House releasing Orry-Kelly's previously unpublished book Women I've Undressed on August 1, and the exhibition Orry-Kelly: Dressing Hollywood opening at Melbourne's Australian Centre for the Moving Image on August 18, the designer is to be feted widely in this country for the first time.

But how did a boy from Kiama become a Hollywood celebrity? Born to tailor and surf-rescue captain William Kelly and socially ambitious mother Florence, Orry was an only child. When he was seven, his mother took him to Her Majesty's Theatre in Sydney to see the pantomime Dick Whittington and His Cat and he was captivated. His favourite toy became a miniature theatre he'd received as a Christmas present - until his father, frustrated that his son was playing with dolls, smashed it.

Studying at local schools - details of his early life are sketchy, but it was likely Kiama Public, then Wollongong District - he enjoyed drawing and painting. At 17, he was sent to Parramatta to stay with an aunt and study to become a banker.

As she researched the film, Katherine Thomson realised Kiama must have been surprisingly sophisticated for a small coastal town, given that it had a dance school, ice and roller-skating rinks, and an arts scene.

"In terms of a rich cultural life, it was probably better than growing up in inner-Sydney Surry Hills at that time," she says.

"But, of course, he was burning to get out."

Once in Sydney, Orry's love of theatre overwhelmed any interest he had in banking and, at 18, he won a one-line part in the bawdy review Stiffy and Mo, starring comedy duo Nat Phillips and Roy Rene.

He drifted into a dissolute life in Sydney's underworld, drinking at Alice O'Grady's Woolloomooloo sly-grog shop, painting portraits of prostitutes and going to the races. He became the foil for a pickpocket known as Gentleman George, and danced with rich wives and widows twice his age for cash. Worried about turning into a "lounge lizard", and scared of Gentleman George after one day refusing to pocket a dropped wallet, he caught a ship to America in 1922.

In New York he met Archie Leach, a handsome 22-year-old Englishman who later changed his name to Cary Grant. Orry roomed with the budding actor in what Armstrong's documentary describes as an "on-again, off-again mateship", though there is the suggestion the relationship was more than Platonic.

In 1931, Orry moved to Los Angeles. When Grant's agent passed on Orry's sketches to Warner Bros executives he was taken on as a costume designer. He hyphenated his names to create the more stylish Orry-Kelly.

The next year he designed gowns for more than 20 movies; the year after that, it was more than 40.

"When everyone was throwing frills, he was doing lines," says Thomson.

"He really appreciated the way women's bodies moved in fabric."

Orry-Kelly spent much of his working life with Hollywood actresses, privy to the insecurities it was his job to keep hidden from the camera.

"The job of discussing a star's defects is both difficult and delicate," he wrote. "Few are perfectly proportioned. One shoulder may slope more than the other; one bust may sag a bit or be less rounded. Often one hip may be inches higher or lower than the other one. Some are knock-kneed, while others wear their legs in parentheses."

Costume designer and author Deborah Nadoolman Landis believes Orry-Kelly's special qualities were shown in his intimate working relationship with an actress who became a star despite lacking the classic looks that studio executives wanted at the time.

"Icons are created in the fitting room," Landis says.

"That's a relationship from the knickers outward. From the inside out, Orry-Kelly helped Bette Davis create her people."

For Casablanca, Landis says the filmmakers needed the audience to fall in love with Ingrid Bergman's Ilsa Lund and Orry-Kelly's costumes were a key factor.

"Her clothes are very, very elegant in the movie. She had to be glamorous enough for us to fall in love with her, but she had to be simple, too."

For Some Like It Hot, Orry-Kelly showed a different kind of artistry, creating clothes for cross-dressing musicians Tony Curtis and Jack Lemmon as well as Marilyn Monroe, whose flaws, he wrote, included short, stocky limbs.

"Marilyn Monroe is someone who famously disliked underwear of any kind," Landis says.

"Orry-Kelly was kind of a match made in heaven because he really understood ... a woman's body and how to hold her up without anything underneath."

Monroe wears two cocktail dresses - one in black and the other in nude - looking as sexy as humanly possible within the constraints of the censorious Motion Picture Production Code.

"There ain't nothin' underneath that dress; that dress is doing all the work," says Landis.

"Really, that's a master designer who is figuring out and working with a cutter-fitter and providing all the support that Monroe needed just by using the dress itself."

For Gypsy, Orry-Kelly helped transform Natalie Wood into the stripper Gypsy Rose Lee. Wood was just 157 centimetres tall and weighed only 41 kilograms, so her most striking costumes featured cushioned bras and padded hips to make her appear more shapely; a vertical line of beads down the front was added to make her look taller.

Australian etiquette queen June Dally-Watkins recalls how big a deal Orry-Kelly was when she stayed in his Beverly Hills mansion as a 25-year-old model in 1952.

"He wanted to show me off, so he'd lend me his clothes to wear and take me out to lunch or dinner," she says.

"Everybody knew Orry. Movie stars would come for dinner and they'd all stop and talk to Orry and he'd introduce me. That's where I met actors like John Wayne, Cary Grant, Judy Garland, Ray Milland, Herbert Marshall and many more. They were all friends of Orry's."

Watkins saw him as warm and friendly but glimpsed another side, too.

"Sometimes he'd drink too much and get a bit cranky. After an altercation with [actress] Merle Oberon, he gave me a gold watch and he said, 'Here, June, take this thing. I don't want to be reminded of that bitch.' Written on the watch was 'To Orry, with my undying love and friendship, Merle Oberon.' A few days later, he asked me to give the watch back."

By the early 1950s, his struggle with alcoholism had taken a toll. Orry-Kelly was living a reclusive life in the Hollywood Hills when the costume designer for 1955's Oklahoma! dropped out just before filming was due to start. At the urging of friend and fellow Australian Dorothy Hammerstein, who was married to the musical's librettist Oscar Hammerstein, Orry-Kelly was brought in. He had become so forgotten his assistant on the film, Ann Roth, had never heard of him.

The musical, with its bright, theatrical costumes, revived Orry-Kelly's career.

"Orry was one of the wittiest human beings you ever met," says Roth, now 83. But even sober, he had a bad temper.

"He would stamp his foot and whatnot. But he was loads of fun."

In February 1964, Orry-Kelly died from liver cancer at the age of 67. His death was barely reported in Australia.

His personal effects, including his Oscars, went to a long-time friend, Ann Warner, Jack's wife, who was at his bedside when he died.

Five decades after his death, Orry-Kelly is back in fashion.