Ashley sports a full-length trenchcoat with booties and a head scarf for a bohemian-chic look at the YSL Belle D'Opium launch party in New York City.
Looks like Ash's bag-lady chic college days are making a comeback. The Row designer mixes a long plaid skirt with leather jacket and leopard-print scarf at the Belvedere pink grapefruit launch in NYC.
Avant-garde Ashley attends the 2010 Lucille Lortel Awards in New York in black, kimono-inspired couture.
Ashley has a totally '70s moment in a shiny jumpsuit—plus a grandma brocade jacket—at New York Fashion Week's amfAR gala.
In an Alexander McQueen lace gown and satin Manolo Blahniks, the Row designer channels Miss Havisham at the Art of Elysium gala in Los Angeles.
Ash pops in a bright blue Erdem frock and her trusty Manolo Blahniks at the In Style-Warner Bros. Golden Globes party. Nicely done!
Ashley lets the feathers fly at the Nine premiere in New York City, rocking a big black coat, matching pants and bag and yellow Manolos.
The girl hearts her Manolos! Ashley pairs her beloved heels with a blue dress under a black coat while hanging with her little sis at a tribute to Tim Burton in the Big Apple.
The sisters rock their old-ladies-who-lunch garb for their induction into the Council of Fashion Designers of America.
So they're funny ears, but they're couture by Maison Michel! Ashley goes with a mouse to complement M.K.'s bunny as the sisters hit the Opening Ceremony boutique opening party in Japan.
At the MuchMusic studios in Canada, Ashley mixes up her separates, pairing a pink blouse with rolled linen pants and Prada heels. Cool or confusing?
The twins are dressed way down to promote Elizabeth and James in Toronto. Ashley wears rolled shorts, a ribbed sweater and Prada sandals.
Ashley's bright, floor-length dress at the CFDA Fashion Awards in NYC is vintage awesome.
This Calvin Klein slipdress is simpler garb than we’re used to seeing on Ash, who's attending the Hangover premiere in L.A.
At the Costume Institute Gala in New York, Ashley drapes her tiny frame in a dramatic white gown from her own high-end collection, the Row.
Ashley sticks to classic black at Mango's store-opening party in New York City.
At the Fashion Group International's 25th Annual Night of Stars, Ash keeps it simple in a strapless navy Calvin Klein dress.
Ashley mixes 'n' matches in a white tux jacket by her own luxe line, the Row, Givenchy belt, Balenciaga blouse and Calvin Klein clutch at the Sex and the City premiere in the Big Apple.
Ashley sports a simple yet classy Calvin Klein Collection ensemble at the CFDA Fashion Awards in NYC.
Ashley looks sleek and smoldering at the Dolce & Gabanna and Penélope Cruz-sponsored charity auction to benefit the Art of Elysium at Chateau Marmont in West Hollywood
Ash goes with an '80s, East Coast ode to Chanel in a little black suit with multiple necklaces at a Karl Lagerfeld fashion show.
Ashley tops her floor-length gown with a black leather jacket for the Art of Elysium gala.
Ashley rocks the reopening celebration of the New Museumin NYC—cohosted by Calvin Klein—wearing a cropped jacket and skinny, ankle-length skirt with peep-toe heels. It's a sophisticated, sexy take on staying warm.
In general, we like Ashley's outfit at this James Taylor performance in the Hamptons, but there are a lot of little details we'd like to tweak: the green skirt peeping above the belt, the wrinkled brown clutch, the ridiculously tall gladiator sandals. Then again, we wouldn't expect anything less daring from an Olsen.
What's fellow celeb sibling Kim Kardashian wearing? Find out in her Fashion Spotlight gallery.