Leighton Meester looks unrecognisable as she goes peroxide blonde!

Move over Blake Lively, there’s a new blonde in town...

Leighton Meester (AKA Blair Waldorf) is known for her long, wavy brunette locks, but she's mixing things up and has gone to the light side.

That's right.

The 'Gossip Girl' star has debuted a short choppy platinum lob and we love it!

Showing off her new look on Instagram, the 32-year-old had us doing a double take at first.

"Having a blonde moment thank you to my hair saviors @auracolorist and Keraphix protein treatment @NexxusNYSalon," she wrote alongside the snap.

Speaking to POPSUGAR, Leighton said she was getting bored of her natural hair colour.

"I recently cut my hair, and thought 'I just want the exact opposite of what I have,'" she said.

"I want to try something completely drastic and different, and I thought this is the right moment to do it. You know when you just get it in your mind and you have to do it?"

According to her colourist, Aura Friedman - who has worked with everyone from Jennifer Lawrence to Lady Gaga - it took around six hours to change the colour of Leighton's hair.

Pictured: Jayne Mansfield

She also revealed the actress' hairstyle was inspired by one of the first Playboy Playmates, Jayne Mansfield.