Not to be outdone by the royal wedding, 165,000 Kentucky residents -- okay, plus a few tourists and celebrities -- dressed up in their finest spring clothes for Derby Day. The first Saturday in May marks an iconic and long-running sports event, social outing and fashion parade. And what's the fashion accessory of choice for the Kentucky Derby? The hat, of course -- and unlike London, they make 'em big in the south. Follow the jump to see the full red carpet review for the running of the roses...

American Idol winner Jordin Sparks beautifully delivered the National Anthem just before the famous race. Her white hat is a perfect blend of style and southern charm.

Erin Andrews looks glamorous in her black and white, wide-brimmed hat, which is elaborately bedecked in feathers, fabric and frills.

Kate Gosselin's hat has a trim of ostrich feathers, a plume of tulle and a smiling reality star in a sexy striped dress underneath it.

Jennifer Tilley and Joey Fatone decided that less is more, wearing a retro-inspired look that nods to the fashions of the 1930s and 40s. Tilly is definitely pretty in pink -- we love the drama of those curving horns on her head.