The fashionistas have invaded the Croisette.

The 66th Cannes Film Festival kicked off Wednesday night with a two-day celebration of the longstanding love affair between the film and fashion worlds rekindled by Prada-packed “The Great Gatsby” and Un Certain Regard opener “The Bling Ring,” about teens obsessed with Louis Vuitton, Versace, Louboutin and Dior, among other brands. The paparazzi will be happy.

But fashion houses in recent years have also started seeking out a different role within the movie world: one that goes beyond dressing stars for red carpets and parties, or designing costumes for their onscreen roles.

Prada, Gucci, Louis Vuitton and other venerated haute couture companies with mega global appeal are increasingly venturing into film from new, and seemingly philanthropic, angles such as film preservation, sponsoring film museums, festivals and schools, and also film production.

Some examples: Gucci, since Frida Giannini took over as creative director in 2006, has donated more than $2 million to Martin Scorsese’s Film Foundation and sponsors film scolarships at NYU and finishing grants at the Tribeca Film Institute. Prada finances shorts by name directors like Roman Polanski’s divertissement “A Therapy,” which screened at Cannes last year, and a series of festival-friendly shorts by women called “The Miu Miu Women’s Tales,” now a Venice Film Festival fixture after bowing in 2012. Louis Vuitton recently opened the world’s only boutique with a built-in screening room, in Rome, and started financing a shorts film competition in tandem with the Rome Film Festival and scholarships at Italy’s Centro Sperimentale film school.

“Fashion is looking for new platforms,” says Milan-based marketing exec Roberta Ciappi.

The key reason, she says, is that supermodels no longer have the iconic appeal they once had in the decade spanning the mid-80s and 90s when fashion brand-building was largely tied to icons like Claudia Schiffer and Cindy Crawford.

“The fashion world is now gravitating towards the real icons, which have always come from the movie world,” Ciappi notes. And a smart way of getting close to actors and directors in these times of economic crisis is to “find an area where they can fill a need.”

Vogue Italy editor Franca Sozzani sees the increase in bridge-building between the fashion and film worlds as “something absolutely beneficial to fashion houses in terms of their image.”

But that’s not necessarily what’s driving them to do it, Sozzani, and other fashion industry experts, point out.

“What’s behind these initiatives is a vision: instead of throwing lots of parties you are doing something that really has a purpose. It’s a useful choice that can open plenty of opportunities for lots of people,” she says

Interestingly, venerated fashion auteur Miuccia Prada, who co-designed the cocktail and evening gowns featured in “Gatsby” and whose Prada Foundation finances the arts in many ways — including an in-the-works contemporary arts museum in Milan, which will have an entire floor dedicated to film — does not see herself as a patron of the arts.

“That’s not the spirit at the basis of her choices,” says a Prada rep. “Rather, it’s a continuous search for knowledge and need to discover that pushes her towards exploring new and different horizons.”

“Miuccia certainly has an artistic approach in her relationship to film,” Sozzani concurs, “while Frida (Giannini) sees the film industry more as a committment to women and woman’s empowerment.”

But Gianinni’s femme empowerment focus did not stop Gucci from financing what is perhaps the most innovative co-ed film and fashion initiative to date: the Venice Film Festival’s Biennale College, which shepherds microbudget pics from development through distribution, providing three projects with €150,000 ($200,000) in cash and a Lido launch in what is touted as a first for a fest.

“It’s a unique opportunity for funding,” says U.S. helmer Tim Sutton who, thanks to Gucci and Venice, is following up his debut “Pavillion” with “Memphis,” which he describes as “a narrative film in a documentary world.”

Former Venice topper Marco Mueller, who now heads the Rome Film Festival, points out that fashion houses are becoming much more part of the conversation in terms of creating a star system in the current age, in which they are constantly changing the models and movie stars they use to promote their brands.

“They gamble on new names; on the fact that the relatively unknown actors they chose will become bigger and bigger,” Mueller notes.

Case in point, Giannini’s close rapport with James Franco, which began in 2008 when Giannini chose the thesp as the face of Gucci Pour Homme perfume and financed some of his shorts when he was at NYU Film School. Franco recently produced docu “The Director: An Evolution in Three Acts” about Giannini, financed by Gucci.

Somewhat similarly, Vuitton and Sofia Coppola have a close collaboration that famously sees Coppola design bags for the label. The bling in “Bling Ring” includes a hot-pink Louis Vuitton Vernis bag, which she did not design.

Vuitton has long-standing ties with the film community in France where its Espace Louis Vuitton gallery commissions and screens auteur-driven shorts.

Of course there are many other fashion houses active in film initiatives, ranging from Giorgio Armani, who was probably the first, to Dolce & Gabbana to eyeware giant Luxottica, whose Persol label is among the most generous film fest sponsors in Italy.

But in terms of film production, the real trendsetter is Agnes B., who in 1997 set up her own Love Streams shingle that has since supplied completion funds and distributed pics by helmers including Claire Denis (“Trouble Every Day”), Vincent Gallo (“The Brown Bunny”) and Harmony Korine, with whom she set up a separate banner called O’Salvation.

“They are the best example you can find today of fashion and film working together to make movies,” Mueller notes.

Love Streams shepherded Gallic musician-filmmaker Quentin Dupieux’s absurdist “Wrong,” which screened at Sundance in 2012 and will be released by the company in September in Gaul.

“When they distribute, they put the whole publicity machine that they created for fashion at the disposal of those films,” he enthuses.