Isla Fisher is unrecognisable after dying her iconic red hair peroxide blonde!

Isla Fisher has gone blonde!

And no, it's not a wig. 

Ditching her iconic red locks, the 42-year-old looked absolutely stunning as she debuted her new platinum blonde hair - and we honestly didn’t recognise her at first!

Tp start the new year off with a bang, the Aussie actress shared a photo of her bold new hair on Instagram, writing: "Go blonde in ‘19 or go home."

And the colour wasn't the only change the mum-of-three made to her trademark hairstyle.

Her characteristically wavy tresses were styled in a straighter, sleek multi-layered cut.

It's not clear if Fisher, who is married to actor-comedian Sacha Baron Cohen, has switched up her 'do for a new movie role or just for a change ... but we are loving her new look!