But there was also much happening off the catwalk.
In a week dominated by celebrity children, it was the turn of Sean Penn's daughter, Dylan, who made her acting debut in a fashion movie.
Meanwhile, the day the civil ceremony took place between George Clooney and wife Amal Alamuddin, Giambattista Valli spoke to AP about his coup in dressing Hollywood's newest bride.
Here are the show reports and highlights of the ready-to-wear collections.
VALLI'S CLOONEY BRIDE COUP
Amal Alamuddin married one-time Hollywood bachelor George Clooney in Venice on Saturday and is quickly becoming one of the most photographed women in the world.
So when the British-Lebanese human rights lawyer made her first appearance after the wedding wearing a Giambattista Valli couture dress on Sunday, it was clearly a major coup for the Paris-based designer.
Alamuddin looked every inch a star, in a long-sleeve macramé embroidered floral gown, with revealing high skirt. Photos of her showing off her wedding ring — and legs — on the Grand Canal with her actor-director husband were beamed around the world.
"It was amazing. It was beautiful," Valli told The Associated Press.
"I was feeling so lucky to have somebody so beautiful — but beautiful in every sense of the way, to interpret my creations," he added.
STELLA MCCARTNEY KEEPS IT REAL
She has a Beatle dad, hosts palpitating, must-see fashion shows in the grandest Paris opera house, and attracts celebrities season upon season.
And yet, there's still something real about Stella McCartney.
With truly wearable fluid silhouettes in denim, silk, organza and knit — her spring-summer 2015 ready-to-wear collection showcased this in droves.
Wide culottes in pastel shades of white, creme and vanilla came alongside utilitarian oversize buckles — slightly aggressive, but never too much.
Alongside these, large perforated holes, heavily stitched hemlines, oversize chain necklaces and leopard printed silk dresses added a whiff of power.
Even the floral looks, of butterfly-like fluttery layers of silk and organza, came in bold patterning that evoked danger.
McCartney said the show was about a "strong feminine attitude." But, most of all, it was about clothes you can wear.
SAINT LAURENT'S FIERCE RAINBOW
The giant square metal set — which rotated aggressively to refract light into all the colours of the rainbow — set the tone for Saint Laurent's spring show: fierce, yet colorful.
It was the 60s and 70s in vogue this Monday, with provocative designer Hedi Slimane working the same glittery formula used in previous seasons.
A red, military Sgt. Pepper-style jacket— accessorized with a round 60s belt, flat black hat and shimmering blue heels — cut a fine look on model-of-the-moment Cara Delevigne.
And turbans made a comeback.
The fierceness was provided by lashings of black leather, studs and the obligatory Slimane-issue stomping models.
But where would the French-born designer be without his traffic-stopping glam rock?
One love-it-or-hate it look in gold leopard print lame had fashion insiders snapping their smartphone cameras.
(For the fashion archive addicts — Slimane also revamped the YSL smoking on several looks, as well as YSL's iconic 1971 green fur coat.)
GIAMBATTISTA VALLI GETS BUSY
With his usual mantra light, white and feminine, Valli produced an archetypally spring show.
In plentiful supply was his signature A-line, short skirt esthetic with sporty shoulders.
The USP for this collection was to be found in its emphasis on floral and organic prints, flashes of blue, and its channeling of the on-trend Balkan jacket and tunic styles.
There were even oversize round Grecian pendants, thick ruffled fabric details on skirts and two-tier fringed dresses.
The busy detailing, like thick stripes up just one pant leg, gave this collection a more heavy-handed feel than is normally associated with the diaphanous designer.
SEAN PENN'S DAUGHTER IN LIMELIGHT FOR FASHION FILM
There has been a lot written about celebrity offspring this Fashion Week and Monday's installment saw Sean Penn and Robin Wright's daughter, Dylan Penn in the limelight.
The up-and-coming model is starring in a new short film called "Rock Roll Ride" to promote popular U.S. shoe maker Stuart Weitzman — which was premiered in Paris.
The film, that's inspired by vintage Playboy magazines, was directed by Julia Restoin Roitfeld — daughter of fashion icon and former French Vogue Editor Carine Roitfeld.
UNDERWATER WITH ELIE SAAB
Elie Saab has let his hair down.
The Lebanese designer — who's normally associated with the fairytale princess — channeled a fun, colour-rich vibe with bright red, blue and vibrant yellow.
The designer said the inspiration was the tropical underwater world: seen in aquatic prints on billowing silk gowns.
But the '70s disco-light decor, long neck scarves, centre partings and the bold lashings of colour gave this a distinctly disco vibe.
The on-trend rib-level A-line mini was high on the catwalk playlist rotation.
The designer is never one to stray too far from his bread-and-butter looks, however, and his column dresses and girly lace detailing was also in the mix.
Some of the looks worked - but the bold colours were at times overbearing.
Thomas Adamson can be followed at http://Twitter.com/ThomasAdamsonAP