He's reportedly set to follow the royal wedding tradition, like his father and grandfather, and don a military uniform made by Savile Row tailors Gieves and Hawkes.
The Prince of Wales and the Duke of Edinburgh both walked down the aisle in Royal Navy uniforms, but William is likely to wear an RAF uniform as he is currently serving as a helicopter pilot with the Search and Rescue Force (Sarf) at RAF Valley in Anglesey, North Wales.
William is also a Knight of the Order of the Garter and on his wedding day is likely to wear the Order's blue sash, with its attached badge, and star, along with his military honour, the Queen's Golden Jubilee Medal.
We think he's going to look simply dashing - what do you think? Let us know in the comments box below.