All the Cool Girls Summer in London

London was calling, and Alexa Chung, Keira Knightley, and Cara Delevingne were more than happy to reply. The ladies were joined by a flock of stylish stars for the annual Serpentine Gallery Summer Party — and they weren't the only ones making the trip across the pond. Model of the moment Irina Shayk bared her gams in an LBD at the UK photocall for Hercules, while Keira returned to the city again later in the week for a Begin Again photocall.

Another actress who has us crushing hard this week is someone new to our hearts: Transformers star Nicola Peltz. With a handful of stylish premiere looks down, the actress continues to blow us away — and a duo of sleek, white dresses in Berlin was no exception. See her and all the lovely ladies who had us falling hard this week. Source: Getty / Steve Granitz

Keira Knightley
Getty | Karwai Tang

Keira Knightley

Keira Knightley in Simone Rocha at the London Begin Again photocall.

Melissa McCarthy
Getty | Alberto E. Rodriguez

Melissa McCarthy

Melissa McCarthy at her hand and footprint ceremony at the Chinese Theatre.

Keira Knightley
Getty | David M. Benett

Keira Knightley

Keira Knightley at the Serpentine Gallery Summer Party.

Suki Waterhouse
Getty | David M. Benett

Suki Waterhouse

Suki Waterhouse in Burberry at the Serpentine Gallery Summer Party.

Cara Delevingne
Getty | Danny Martindale

Cara Delevingne

Cara Delevingne at the Serpentine Gallery Summer Party.

Gemma Arterton
Getty | David M. Benett

Gemma Arterton

Gemma Arterton in Prabal Gurung at the Serpentine Gallery Summer Party.

Samantha Barks
Getty | Fred Duval

Samantha Barks

Samantha Barks at the Serpentine Gallery Summer Party.

Irina Shayk
Getty | Tim P. Whitby

Irina Shayk

Irina Shayk at the London Hercules photocall.

Liv Tyler
Getty | Raymond Hall

Liv Tyler

Liv Tyler in Proenza Schouler while out in New York.

Jordana Brewster
Getty | D Dipasupil

Jordana Brewster

Jordana Brewster in Houghton at the Mr. Clean Summer Fashion Party.

Riccardo Tisci and Naomi Campbell
Getty | Stuart C. Wilson

Riccardo Tisci and Naomi Campbell

Riccardo Tisci and Naomi Campbell at The Serpentine Gallery Summer Party.

Melissa McCarthy

Melissa McCarthy

Melissa McCarthy at the LA premiere of Tammy. Source: Getty / Steve Granitz

Toni Collette
Getty | Noam Galai

Toni Collette

Toni Collette at the New York premiere of A Long Way Down.

Zendaya
Getty | Charley Gallay

Zendaya

Zendaya at the Letters to Men I Have Loved book launch.

Nicola Peltz
Getty | Luca Teuchmann

Nicola Peltz

Nicola Peltz in Stella McCartney at the Berlin premiere of Transformers: Age of Extinction.

Kerry Washington
Getty | Jason LaVeris

Kerry Washington

Kerry Washington in Dolce & Gabbana and Casadei at the BET Awards.

Keira Knightley
Getty | Rob Kim

Keira Knightley

Keira Knightley at SiriusXM Studios.

Chloë Moretz
Getty | Albert L. Ortega

Chloë Moretz

Chloë Moretz in Dolce & Gabbana at the Saturn Awards.

Natalia Vodianova
Getty | Michel Dufour

Natalia Vodianova

Natalia Vodianova in Louis Vuitton at Menswear Fashion Week.

Jennifer Lopez
Getty | Alexander Tamargo

Jennifer Lopez

Jennifer Lopez at the iHeartRadio Ultimate Pool Party.