But there are two guests of honour who have already showcased their wedding style – Kate's sister and maid of honour Pippa Middleton, and Chelsy Davy, the rumoured guest of best man Prince Harry.
1. Red lace dress by Erdem. 2. Asymmetric fascinator headband, by Accessorize. 3. Heeled pumps by Balmain. 4. Coat with ruffle detail by Rachel Roy.
At a mutual friend's nuptials at Alnwick Casle in February, both ladies gave a glimpse of their wedding guest look. And, when it comes to dressing up for such a celebration, Pippa and Chelsy seem to be on the same sartorial page.
Both chose to wear a short, brightly-coloured dress, teamed with a coat and black clutch bag.
Pippa, 27 showcased an eye-catching long-sleeved lace dress in red, while Zimbabwe-born Chelsy, 25, opted for an electric blue number – one of the most in-demand colours of the season – with detailed draping.
1. Hair clip with feather and jewel detail, by Accessorize. 2. Fan shaped clutch, by Topshop. 3. Double breasted woolen coat, by J. Crew. 4.Blue silk dress with drape detail, by Tibi. 5. Heeled pumps, by Jimmy Choo.