But it was the Disney starlet's pleated dress that really caught our eye. Why? The Saturdays' Mollie King stepped out in the very same number in August.
With distinctive scalloped waist detailing and a gorgeous green and blue colour palette, the girls' dress is a standout design from celebrity-favourite label, Three Floor.
The Saturdays have been championing the brand for months and now it seems Bella's fallen in love with it too!
Bella opted for big curls, embellished pastel nail art and even an ornate mask.
Mollie wore the Model Behaviour dress, £130, with chunky platform shoes and a simple black clutch as she partied in London's Mayfair.
Both looked seriously hot, but who do you think wore it best? Let us know by voting in the poll below.