Fashion Looks of the Week By InStyle Editors InStyle Editors Facebook Instagram Twitter Our editors and writers comprise decades of expertise across the beauty, fashion, lifestyle and wellness spaces in print and digital. We prioritize journalistic integrity, factual accuracy, and also having fun with every story we share. InStyle's editorial guidelines Updated on March 27, 2015 @ 11:31AM Pin Share Tweet Email Trending Videos Photo: Michael N. Todaro/Getty Images for NYCWFF Looks of the Week 01 of 22 Kate Middleton Mark Cuthbert/UK Press via Getty Images Kate Middleton made a bold move, fashion-wise, and turned heads at the Addiction Autumn Gala Evening in a sexy cut-out Temperley London LBD with delicate panels that revealed a nude slip underneath that she styled with a beaded clutch and black pumps. 02 of 22 Sienna Miller Gregg DeGuire/WireImage Sienna Miller attended the International Medical Corps's Annual Awards dinner ceremony in a burgundy off-shoulder Erdem design with a sheer yolk and floral beadwork sprinkled all over. Her shoe of choice? Black peep-toes. 03 of 22 Michelle Monaghan Taylor Hill/FilmMagic To support designer Joseph Altuzarra at the 31st Annual Fashion Group International's Night of Stars event, Michelle Monaghan stunned in Altuzarra separates-a sheer top layered under a tuxedo vest with black tailored pants. Graziela Gems earrings, a Melinda Maria ring, an EFFY Jewelry bangle, a metallic clutch and Altuzarra heels completed her sharp look. 04 of 22 Karlie Kloss Pascal Le Segretain/WireImage Karlie Kloss struck an alluring note at the launch of the de Grisogono "Crazy Skull" watch in a plunging black number, accessorizing with a single statement earring, the skeletal timepiece (naturally), and black pumps. 05 of 22 Olivia Munn Cindy Ord/Getty Images Olivia Munn channeled Black Swan at the 2014 American Ballet Theatre Gala in a black feathery Lanvin frock, complete with a polka-dot clutch, a ballerina-esque top knot, and black ankle-strap pumps. 06 of 22 Lupita Nyong'o Richard Young/Rex/REX USA Lupita Nyong'o co-hosted the grand opening of Bally's first London flagship store, selecting a look in head-to-toe Bally for the occasion-a custom ochre long-sleeve top refreshingly paired with a dusty pink full skirt, with a forest green leather belt. A dark cherry cashmere-suede Bally trench, a color-blocked handbag, and two-toned sandals rounded out her charming on-point ensemble. 07 of 22 Camilla Belle Michael Kovac/Getty Images for Restoration Hardware Camilla Belle celebrated the Restoration Hardware WeHo opening in ladylike cherry-red Carolina Herrera separates with geometric accents. A metallic box clutch and embellished pumps were the finishing touches. 08 of 22 Kaley Cuoco Jason LaVeris/FilmMagic Kaley Cuoco-Sweeting made a sharp entrance at the ASPCA Compassion Awards in a sleeveless tie-front button-down that she smartly styled with wide-leg Issa trousers, accessorizing with Melissa Kaye Jewelry earrings, a Vita Fede necklace and bracelet, a metallic clutch, and black pumps. 09 of 22 Kate Middleton Arthur Edwards - WPA Pool/Getty Images The Duchess of Cambridge made a striking appearance at the Wildlife Photographer of the Year Awards Ceremony in a bespoke pale jade draped Jenny Packham gown with a thigh-high slit that revealed a mid-length skirt underneath. Monica Vinader jewelry and nude accessories rounded out her look. 10 of 22 Jaime King Donato Sardella/Getty Images Jaime King dined out in an incredibly chic white knit Wes Gordon column that she accessorized with Jennifer Fisher jewelry, a glittery box clutch, and white cut-out pumps. 11 of 22 Reese Witherspoon Stefanie Keenan/Getty Images for CFDA Reese Witherspoon stunned in a blue-and-black floral print Oscar de la Renta frock, complete with a polka dot L.K. Bennett clutch, Jennifer Meyer jewelry, and black-and-white Giuseppe Zanotti heels. 12 of 22 Dianna Agron Stefanie Keenan/Getty Images Dianna Agron made a ladylike appearance at the CFDA Awards in a violet lace crystal-embellished separates that she styled with Irene Neuwirth jewelry, metallic personalized Edie Parker clutch (scrawled with her name), and silver pumps. 13 of 22 Jessica Alba Han Myung-Gu/WireImage Jessica Alba flaunted her toned midriff at Seoul Fashion Week in a pretty pink floral appliqued Tanya Taylor crop top, offsetting the flirty vibe with a cool pleated leather midi skirt, a black purse, and black ankle-strap heels. 14 of 22 Blake Lively J. Countess/Getty Images Expectant mom Blake Lively glowed on the red carpet at the Angel Ball 2014, lighting up in a radiant pale yellow silk long-sleeve Gucci column with a plunging silver crystal-embroidered neckline gown, complete with Lorraine Schwartz earrings. 15 of 22 Michelle Williams Pierre Suu/GC Images Michelle Williams celebrated the inauguration of Fondation Louis Vuitton in a playful retro-inspired printed Louis Vuitton LWD, giving her look a futuristic edge with a black-and-red box LV clutch and too-cool platform LV boots. 16 of 22 Kerry Washington Jon Kopaloff/FilmMagic Kerry Washington struck a pose in a sleek one-shoulder Calvin Klein Collection design with a foldover neckline that revealed a dash of cornflower blue. A black-and-white Thale Blanc clutch and Louboutin pumps completed her look. 17 of 22 Jennifer Lawrence Jason Merritt/Getty Images for ELLE Jennifer Lawrence made a sweet appearance, stepping out in a lovely belted lace Oscar de la Renta LWD that she styled with a black-and-gold Rodo clutch, rings by Graziela Gems and Le Vian, and Louboutins. 18 of 22 Rachel McAdams George Pimentel/WireImage Rachel McAdams stunned at the 2014 Canada's Walk of Fame Awards in a sweeping strapless black-and-white silk chiffon Zuhair Murad Couture gown, injecting a touch of shine with diamond Kwiat rings and Norman Silverman earrings. 19 of 22 Rooney Mara Elisabetta A. Villa/WireImage Rooney Mara gravitated toward her go-to for the premiere of Trash during the 2014 Rome Film Festival, selecting contemporary black separates from Balenciaga, which included an off-the-shoulder crop top with sheer yoke and sleeves and an embroidered sheer skirt, with black pumps. 20 of 22 Lily Collins Vittorio Zunino Celotto/Getty Images Lily Collins hit the Love, Rosie photocall during the 2014 Rome Film Festival in a sleek ivory crop with matching high-waisted wide-leg pants, both by Pamella Roland, styling her look with a gold timepiece, a Melissa Kaye Jewelry ring, and bold red lip. 21 of 22 Lupita Nyong'o David M. Benett/Getty Images for Cafe Royal As queen of monochromaticism, Lupita Nyong'o stepped out for the Sindika Dokolo Art Foundation in a head-to-toe black, accessorizing her ruffled Fitriani LBD with a mini ladylike bag and black pumps. The crown jewel of her look? Her pretty delicate headband. 22 of 22 Chrissy Teigen Michael N. Todaro/Getty Images for NYCWFF Chrissy Teigen showed off her enviably long, lean legs with tailored cream shorts that she teamed with an optic white A.L.C. blouse, jewelry by EF Collection and Vita Fede, and white pumps.