Paul McCartney cheers on Stella at Paris fashion week
The singer, along with wife Nancy Shevell, headed a host of names on the front row including Ringo Starr's wife and former Bond girl Barbara Bach, model Twiggy, actresses Salma Hayek Pinault and Angie Harmon, singer Sharleen Spiteri and model Natalia Vodianova.
On the catwalk, flowers were everywhere with summer suits, skirts and bustier tops in floral jacquard and silk slip dresses with a floral motif.
Necklines were plunging and fabric often sheer in a palette of "ink, brick and natural tones... natural linen and powder colours".
Famous faces were not restricted to the front row with British model-of-the-moment Cara Delevingne appearing at the show alongside Australia's Miranda Kerr.
French fashion house Leonard, meanwhile, continued the floral theme with bright pink and flesh pink peonies on tops, dresses and skirts and a sheath dress embroidered with giant flowers.
Other looks included an Art Nouveau-style print and for evening a pointillist black tuxedo dress in soft silk.
And there were flowers at Italian designer Giambattista Valli's show too with designs -- from shorts to dresses -- covered in romantic appliqued pansies.
Other eye-catching looks included dresses that were split to the waist and/or sheer, revealing big black knickers.
Elsewhere, Hedi Slimane's latest show for Saint Laurent was scheduled to be held later Monday.
The show -- along with New York fashion star Alexander Wang's second collection for Balenciaga -- is among the most anticipated of the season.
The innovative designer shook up menswear during his time at Dior from 2000 to 2007 with narrow trousers in a "skinny" style that took off with mass-market designers worldwide.
Chanel designer Karl Lagerfeld shed weight to be able to get into a Slimane suit and stars Mick Jagger and Pete Doherty made it their own too.
But the French designer has ruffled feathers in the fashion industry. And his decision to break with tradition and not take questions backstage has left many baffled by his Saint Laurent creations.
Although regarded as visionary by some, critics have seen some of his more recent looks as grungy and "not Yves Saint Laurent".
Nine days of ready-to-wear fashion for spring/summer 2014 are due to wrap up on Wednesday.
Tuesday will see Lagerfeld's show for Chanel while Marc Jacob's Louis Vuitton show will kick off the final day.