Hot mama! Alessandra Ambrosio, 33, looked killer one week after the VS Fashion Show in a knockout dress that showed off a lot of leg. (Photo by Thos Robinson/Getty Images for ACRIA)
Twiggy? No, it's Emma Roberts looking absolutely adorable in a flirty pink mini dress with a fun printed collar. Nude Mary Janes and pixie cut completed her '60s-inspired look. (Photo by Evan Agostini/Invision/AP)
Reese Witherspoon, 38, looked adorable while pumped gas in a leopard-print skirt and black pumps. (Photo by GONZALO/Bauer-Griffin/GC Images)
It's no secret that James Marsden is smokin' hot, but the "Best of Me" actor, 41, looked even better than his usual sexy self in a maroon suit and his signature smoldering stare. (Photo by Evan Agostini/Invision/AP)
Anna Kendrick, 29, looked perfectly polished in a simple black-and-white dress and slicked-back hair. Natural makeup and a little black clutch finished off the minimal look. (Photo by Evan Agostini/Invision/AP)
Katie Holmes, 35, looked better than ever in a pleated skirt, nude pumps and healthy glow. A messy updo and red clutch completed her chic look. (Photo by Evan Agostini/Invision/AP)
Jessica Chastain, 37, was the lady in red in a sophisticated wrap dress and her fiery locks. (Photo by ESBP/Star Max/GC Images)
Jaime King, 35, kept it casual at the park in light-wash skinnies and an oversized sweater. A mini Dior bag and her son's sand bucket completed her day-at-the-park look. (Photo by Bauer-Griffin/GC Images)
Kendall Jenner, 19, kept warm in New York in layers upon layers. Luxe pieces like leather leggings and her high-end bomber jacket elevated the look beyond what many might call "homeless chic." (Photo by Raymond Hall/GC Images)
Actress Rose Byrne, 35, looked pretty as can be in a playful minidress and blunt bob. (Photo by Evan Agostini/Invision/AP)
We can't take our eyes off of Orlando Bloom's casual red carpet look. "The Hobbit" star, 37, paired his suit with a simple button-down shirt and sneakers. (Photo by Gregg DeGuire/WireImage)
Nikki Reed, 26, was a class act in a midi-length pencil dress in a subdued print. Undone hair and her winning smile completed the look. (Photo by Richard Shotwell/Invision/AP)
Olivia Munn, 34, turned heads in a flirty tangerine cocktail dress. Quirky Valentino accessories added a perfect touch of polish to the fun red carpet outfit. (Photo by Evan Agostini/Invision/AP)
Kim Kardashian, 34, was a bit more covered up than usual in a army green body con dress and military-inspired leather trench. (Photo by Raymond Hall/GC Images)
Director Sofia Coppola, 43, looked effortlessly chic in a simple black frock with a fun collar. (Photo by Dimitrios Kambouris/Getty Images)
Emily Blunt, 31, looked gorgeous in an dramatic gown in a beautiful emerald hue. (AP Photo/Kamran Jebreili)
A new week just means more red carpets, events, parties and galas for Hollywood's sexiest stars.
This week, Alessandra Ambrosio, 33, stood out in an extremely daring gown that only a supermodel could get away with. The Victoria's Secret Angel is used to baring (almost) all on the catwalk, but this time, she flaunted her hot bod on the red carpet.
Emma Roberts opted for a more conservative, yet totally adorable, look for a separate event. The "American Horror Story" actress, 23, channeled the '60s in a hot pink number with a fun collar. Mary Janes and her pixie cut completed her retro look.
Reese Witherspoon, 38, was spotted pumping gas in a casual chic outfit that consisted of a cheeky leopard-print skirt and pointy stilettos. A messy bun and oversized scarf kept the look daytime-friendly.
See the rest of our picks for this week's sexy celeb style.