This Week's Best Dressed: Amanda Seyfried, Rachel McAdams, Lily Collins, Amber Heard, Julianne Hough [SLIDESHOW]

This week's best dressed stars include "Lovelace's" Amanda Seyfried, Lily Collins of "The Mortal Instruments: City of Bones," Rachel McAdams's return to the red carpet in London, Amber Heard, Johnny Depp's rumoured girlfriend, and Julianne Hough at the "Paradise" premiere.

Amber Heard has not one, but two spots on this week's best dressed list. The "Paranoia" star was a stunner in Michael Kors when she stopped by "Jimmy Kimmel Live!" Her look was typical Amber - body-conscious, chic, flattering. She paired a black, scoop-neck top with a very risqué, black-trimmed skirt. The camel colored skirt may have been below-the-knee, but its slit was thigh-high. Amber's other winning outfit was a white J. Mendel cap-sleeve frock that showed off the actress' more demure side.

The much anticipated "Lovelace" starring Amanda Seyfried and Sharon Stone, premiered in Hollywood on August 5. At previous "Lovelace" screenings and press events, 55-year-old Sharon Stone managed to steal the spotlight from Amanda. Not so at the Hollywood premiere. The 27-year-old joined this week's best dressed in a dazzling Gucci halter dress. Amanda Seyfried flashed some side boob in her smouldering pebble texture metallic dress, which she paired with her favourite Givenchy sandals.

It's been a while since Rachel McAdams made a red carpet appearance. At the London premiere of "About Time" on August 8, the 34-year-old wasted no time making her fans remember what they missed! Rachel looked simple, yet stunning in a Roksanda Ilincic top and skirt in the palest silver, with a statement-making reflective belt, and a bold stripe running through its back.

No wonder this "Mortal Instruments: City of Bones" star has been trying on edgier and sexier styles. Lily Collins, newly single, seemed poised for a fun night when she wowed in acid yellow Versace for a visit to "Late Night with Jimmy Fallon."

Julianne Hough rounds out this week's best dressed list in Moschino. The former "Dancing with the Stars" pro looked fantastic in her contrasting collar coat dress and multi-strap Stuart Weitzman heels.

Start the slideshow for a peek at this week's best dressed stars.

For more celebrity style, read:

Olivia Wilde, Kate Hudson, Deepika Padukone: This Week's Best Dressed in Red, White, And Orange [SLIDESHOW]

Amanda Seyfried: 'Lovelace' Star Shines at Premiere with Sharon Stone Hot on Her Heels [PHOTO]

Julianne Hough: 'Paradise' Premiere in White; See Her Best White Outfits [SLIDESHOW]