The Late Show With David Letterman, New York

Arriving at the Ed Sullivan theater for her appearance on the Late Show with David Letterman, Leighton Meester looked divine wearing a grey silk Lanvin Spring 2009 one-shoulder top with black high-waisted pants.

She paired her look with an Azzedine Alaia wide double layered belt, grey Christian Louboutin metallic ‘Ronda Dina’ platforms whilst carrying a grey Louis Vuitton Biseta clutch.

When Leighton departed the Ed Sullivan theater she had changed into a Proenza Schouler ivory jumpsuit, which was belted and had an exposed zipper.

You may recognise her stunning red Brian Atwood red pumps, which were featured in Graeme Black’s Spring 2010 presentation during London Fashion Week.

She also carried a Proenza Schouler Resort 2010 orange and black trimmed bag.

On The Gossip Girl Set, New York

We’ll have to wait until this episode airs, but I think under her robe Leighton is wearing the same Oscar de la Renta Fall 2009 gold and chestnut dress we saw on Anna Wintour recently.

Another day on set Leighton was spotted wearing a very expensive Oscar de la Renta embroidered stretch cashmere sweater with a cute fly away floral skirt.

Wearing a 3.1 Phillip Lim dress and a leather jacket, Leighton carried a Mulberry Daria leather satchel.

Whilst picking out some new thread with her stylist Logan Horne, Leighton looked very casual wearing a Riller and Fount top, with her Chloe Sevigny for Opening Ceremony boots and a Current Elliott Sleeveless JJ vest.

All caught up on Leighton.  Kate Beckinsale and Rihanna to follow at some stage.

Credit: Style.com & Wireimage