That is, apart from a handful of people.
The singer caused a stir earlier this month when she said she wants to launch her own fashion label — so could this appearance have been a reconnaissance mission?
Here are the highlights of Thursday's fall-winter ready-to-wear shows.
RIHANNA'S SURPRISE VISIT AT BALMAIN
The singer, who had plum lips and wore a revealingly plunging terre verte belted Balmain jacket without a bra, arrived at Paris' Hotel de Ville with heavy security, and was greeted by friend and designer Olivier Rousteign, who hugged her and gushed: "She's the hottest girl in the world."
The well-dressed Barbadian superstar has her eyes set on the fashion industry — and not just as the face of Balmain.
When asked Thursday if she was here to get inspiration for her own brand, she hinted she's attending Paris Fashion Week to get ideas.
"I love Balmain and can be inspired by (Rousteign's) clothes. I'm inspired by everything here (in Paris)," she told The Associated Press, her only comments before being whisked away.
Rihanna is no stranger to the industry: she's created collections for two fashion labels before for Armani in 2011, and for high-street brand River Island. She may hope to tread a path similar to rapper Kanye West, who now has his own fashion brand, shows in Paris and is a regular attendee at runway shows.
BALMAIN SAYS 'L'AFRIQUE, C'EST CHIC'
Zebra stripes, leopard print, beaded jackets mixed with khaki colours, flak pockets and safari pants.
Yes, this was Africa — at least, Balmain's opulent and decadent version of it.
And the exotic musing helped Rousteign produce a subtler collection than usual.
The brashness was still there of course in a citrus yellow fleece sweater or in the waists which were cinched to within an inch of life.
But the fall-winter collection saw some of the best looks seen so far this season, like a petrol blue knotted rope sheath with a regal-feel twinned with beige cuffs that resembled African bracelets.
L'afrique, c'est chic!
RIHANNA UPSTAGES CATHERINE DENEUVE
Rihanna caused a media scrum as she entered the Lanvin show in a beige trilby hat.
With the sort of fame the it-pop star possesses, it's inevitable that even the most iconic of vintage stars will be upstaged.
This was the case with Catherine Deneuve, a main fixture at Paris Fashion Week, who looked nonplussed in her front row seat as people busied around the singer.
One thing's certain: the "Belle de Jour" star won't be too bothered, since at 70, she's seen it all before.
LANVIN USES FUR LIKE COTTON
To the set of an age-old movie studio with flood lighting Alber Elbaz produced yet another symphony of excitement, nostalgia and innovation for Lanvin.
The show in the Left bank Ecole des Beaux-Arts was varied — Elbaz famously designing to give women as much choice as possible.
The first aria: feathered riding hats alongside black, brown and white asymmetrical tweed coats had a swagger of the 18th century, with horizontal lines and fringing that was so loose it looked feathered.
The conclusion was 1930s satin dress nostalgia.
But the best segment was the fur climax in the middle. (Vegans stop reading.)
Elbaz used fur extravagantly and with style: in skirts, jackets, dresses — and even a black fur rucksack that had fashion insiders gasping.
Then he proposed a whole new concept: button down fur.
It featured in bands and lapels — and one model capped it all by sporting a grey fur bust.
BODY BAGS AND DRIED BLOOD ARE TRENDY THIS SEASON
Rick Owens injected Thursday's proceedings with a splash of dried blood and deathly musing.
The eccentric American designer continued using the high wading boots of his menswear show, but this time he mixed the black and pearl palette with what the program notes described as "dried blood." Normal people might call it burgundy.
Elsewhere, strangeness took on a new form altogether in abstract, enveloping silhouettes that that were sweetly described as "bodybags," which possessed high turtle necks and long billowing sleeves.
Naturally for an oddball like Owens, the show ended with a completely unrelated science-fiction vibe: C3P0 style knee caps on boots, with shoulder stripes and high round necks like Star Trek uniform.
With Owens there is always a mad unity in the disparate styles. Needless to say, his was a very cool show.
FASHION ICON CLAUDE MONTANA HITS DRIES VAN NOTEN EXHIBIT
He's was one of the biggest fashion icon of the 1980s, who all but disappeared from public view after his company went bust in 1997, but Claude Montana made a rare appearance turning up for the launch Belgian designer Dries Van Noten's Paris retrospective.
"It a wonderful show actually. I love the colours and shapes. It's beautiful," Montana told the Associated Press, inside the sprawling exhibit at Paris' Musee des Arts Decoratifs where he walked around discreetly and was hardly recognized.
The designer, one of Alexander McQueen's and Riccardo Tisci's biggest influences, and was good pals with Cher in her heady days, was one of the hottest fashion tickets in the 1980s. He set the standard for opulence and excess in his fashion presentations, but in the 1990s he fell off the map.
Fashion shows have reined in their excess somewhat in recent years, especially due to the financial crisis. But the discreet 66-year-old says he still admires the presentations of the Paris fashion industry nowadays.
The Nina Ricci show progressed from covered up chic to complete see-through in a feminine show that channeled designer Peter Copping's fascination with the vintage and romantic.
And, of course, the signature flowers.
Nostalgic colours like silvery purple, deep plum and burgundy mixed up with sequined dresses with hints of the 1930s. Elsewhere, there were some dropped waists and one great black and white flying jacket with huge 1970s lapels.
The use of fur was notable, appearing inventively as luxuriant streaks or insets on capes and jackets.
The final series of high, sheer gowns had a feel of a sensual prude that might have been borrowed from Valentino.
Thomas Adamson can be followed at www.twitter.com/ThomasAdamsonAP