After the ceremony there will be a reception at St George's Hall for the couple and congregation, understood to be a lunch for close family, friends and perhaps some charity representatives – believed to be 240 to 300 in all – where speeches will be made.
A short gap between afternoon and evening festivities is expected to follow.
Members of the public will then be able to get a glimpse of the newlyweds as they undertake a carriage procession from Windsor Castle and back.
It will see them travel down Castle Hill, along the High Street and then along Sheet Street, Kings Road and Albert Road, before returning to the castle along the Long Walk.
Meghan Markle are hugely grateful for the many good wishes they have received since announcing their engagement.
The couple will then make their wedding vows in front of the Archbishop of Canterbury, Justin Welby. We've spotted her in these classic ' Matilde' pumps before, so they're clearly a favourite of Meghan's.
Harry, 33, will be the first senior royal in modern times to be granted a Church of England wedding despite marrying a divorced woman. With their versatile and timeless aesthetic, we're not surprised she turned to them again on this high profile occasion.
A spokesman for Kensington Palace said Harry and Meghan's 'short journey' would 'provide an opportunity for more people to come together around Windsor and to enjoy the atmosphere of this special day'.
Royal sources told the Daily Mail that there will be, in effect, four parts to the day, with festivities ending with a reception complete with a whisky bar.