Stars began arriving at day one of The Jingle Bell Ball at the O2 Arena in London today (Sat. Dec 4).

The Black Eyed Peas, who released their sixth album The Beginning in November, were there to do their thing. Fergie arrived wearing a leopard print sun hat and dark sunglasses while Will.i.Am rocked his Lego accessories.

Singer Nicole Scherzinger was also in attendance with a very retro hair-do and outfit, looking better than ever.

More pics below!