The comedian, who is best known for his outrageous alter ego Keith Lemon, threw a huge bash to mark his big day at London bar Gilgamesh and was joined by a whole host of famous faces.
Also joining Keith were the likes of Jodie Marsh who dressed as a character from Avatar, I’m A Celebrity… Get Me Out Of Here Now! presenter Laura Whitmore who came as King Kong character Ann Darrow and Mel C and Emma Bunton who dug out their old Spice Girls outfits for the occasion.
Meanwhile Holly, 32, dressed up as country music star Dolly Parton and Fearne Cotton took a break from looking after her baby son, Rex, to wear a rather fetching cupcake outfit.
Where was our invite Leigh?!
Check out some more of our favourite looks from the night below.