The wedding itself will take about an hour, but festivities around the event will see food stalls and big screens installed throughout Windsor.
Extra trains to and from London will also be put on for those who want to travel down to catch the big day.
-> 12 things you probably won't understand if you're not form YorkshireMeghan Markle's parents, Thomas Markle and Doria Ragland, will fly in for the wedding, while Prince William will be Best Man.
The statement from the Palace
"We are now just over two weeks away from the wedding of His Royal Highness Prince Henry of Wales and Ms Meghan Markle. As they have travelled around the UK in the months since their engagement last November, Prince Harry and Ms Markle have been incredibly grateful for the support they have received from members of the public.
"We said from the outset that Prince Harry and Ms Markle were keen to make sure that members of the public would have the opportunity to feel part of the celebrations on their wedding day.
"This is their way of expressing their gratitude for the messages of support they have received from around the UK, the Commonwealth, Ms Markle's home country of the United States, and right around the world. In today's briefing I want to share more details of what people can expect to see in the day's leading up to the wedding, and on the day itself, and explain what the public can expect in Windsor."
-> Local Election in Leeds 2018: Full results from LeedsWho's invited from the family?
"The first thing I would like to share is that Prince Harry and Ms Markle are very much looking forward to welcoming Ms. Markle's parents to Windsor for the wedding. Mr Thomas Markle and Ms Doria Ragland will be arriving in the UK in the week of the wedding, allowing time for Prince Harry's family, including The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, and The Duke and Duchess of Cambridge, to spend time with them before the big day.
"Both of the bride's parents will have important roles in the wedding. On the morning of the wedding, Ms Ragland will travel with Ms Markle by car to Windsor Castle. Mr Markle will walk his daughter down the aisle of St George's Chapel. Ms Markle is delighted to have her parents by her side on this important and happy occasion.
"In addition to having the support of The Queen, his father The Prince of Wales, and his brother Prince William as Best Man, Prince Harry is also keen to involve his mother's family in his wedding. All three siblings of Diana, Princess of Wales will be in attendance and Lady Jane Fellowes will give the reading. Prince Harry and Ms Markle both feel honoured that Lady Jane will be representing her family and helping to celebrate the memory of the late Princess on the wedding day.
"As we said back in November, this wedding will be guided by tradition, allowing everyone to celebrate what makes Royal Weddings so special, but also one which reflects the personalities of Prince Harry and Ms Markle. We have been announcing details over the last couple of months and in the final week ahead of the wedding you can expect to hear more about the arrangements.
The Instrument of Consent;
Details of the Bridesmaids and Page Boys;
The work of florist Philippa Craddock and the Crown Estate gardeners who have been growing and preparing the flowers that will fill the church;
An update from Claire Ptak, the baker who will make the wedding cake, and the chefs who have been working in the Palace kitchens to make the final preparations and;
We will publish the full Order of Service on the website on Saturday morning so members of the public can follow the service at home.
Preparations in Windsor - including foot stalls and big screens
On the day itself we expect Windsor to be very busy. The council has worked with partners including Thames Valley Police to plan what will be a fantastic day of celebrations.
As the Royal Borough of Windsor has said, work is well underway to ensure the occasion is a memorable and joyous one for all involved and they are working closely with a wide range of partners.
Rail operators will be putting on extra trains and there will be park and walk and park and float services to help people get into town. Visitors are encouraged to plan ahead and book all travel arrangements early so they can make the most of their trip. I would very much appreciate the media's assistance in spreading the message that visitors to Windsor will have a chance to be part of a very special day, but those who will be heading to the town really do need to plan their journeys carefully.
The Royal Borough has confirmed that preparations include:
A 6,000 space pre-booked car parking area at the Review Ground, just off the Long Walk;
Food stalls and facilities, including big screens showing live footage of the wedding and Procession, on the Long Walk and in Alexandra Gardens;
Viewing areas along the whole Procession Route (Castle Hill, High Street, Sheet Street, Kings Road, Albert Road and the Long Walk);
A team of 140 Royal Borough Ambassadors have volunteered to help steward the event and assist visitors throughout the day;
The town centre will be decorated with bunting and ceremonial banners along parts of the Procession Route and;
Live entertainment from local groups throughout the town centre.
In order to make sure everyone can get through expected traffic, the members of the public who have been invited to be inside the grounds of Windsor Castle for the wedding will be arriving from around 0900hrs. As a reminder, 1,200 people have been nominated by Lord Lieutenants from across the country for their work supporting their communities. Many of these people are sharing their stories with their local media and supporters - the couple are very pleased that their wedding has provided a platform to celebrate the inspiring work of community and youth leaders from around the UK.
The first thing these people gathered will see on the morning of the wedding will be the arrival of guests between 0930hrs and 1100hrs. Guests will be arriving at the Round Tower by coach and will be seen walking to the South Door of St George's Chapel.
The Royal Family's arrival
Members of The Royal Family will begin to arrive from 1120hrs, and enter St George's Chapel via the Galilee Porch. Some will be on foot, and others will arrive by car.
Prince Harry and his brother The Duke of Cambridge will arrive at St George's Chapel most likely by foot and will enter via the West Steps. This will allow Their Royal Highnesses to acknowledge all of the people gathered in the Castle precincts, including the 200 charity representatives gathered in the Horseshoe Cloister at the bottom of the steps.
Also around the time Royal Family arrivals begin, a pooled media facility will cover Ms. Markle and Ms. Ragland's departure from the bride's overnight location. We expect the journey into the Castle to take them along part of the Long Walk, allowing members of the public gathered there to see the car as it passes. There will also be a brief stop at the Castle where Ms. Ragland will head onto the Chapel and Ms. Markle will be joined by some of the Bridesmaids and Page Boys before she continues her journey to the church, where she will enter via the West Steps.
The Service will take around an hour, and we look forward to announcing more details of this in the weeks ahead.
After the Service has concluded, the newly married couple will process out of the church and acknowledge the 200 representatives of Prince Harry's charities gathered in the Cloister. The couple are delighted that these people who will be such an important part of their official work in the years to come will be the first people they see after their wedding.
As the couple step into their Carriage, close family members will gather on the West Steps to wave them off on their Procession. As a reminder, we expect the Carriage Procession to take just under 25 minutes. Prince Harry and Ms. Markle are very much looking forward to this part of the day. It will be their chance to express their gratitude for the goodwill and warm wishes they have received from all quarters in the months since their engagement.
Members of the congregation will file out of the church onto the grass to see the start of the Procession before walking to the reception at St George's Hall. All guests will be attending the reception.
The public elements of the event will be over at this stage. The final thing you can expect to see is the Bride and Groom departing Windsor Castle for the evening reception at Frogmore House.
In the days that follow, we will facilitate interviews with some of those who have been involved in the wedding, as happened in 2011, for example with the hairdresser and dressmaker.
The formal photographs, which will be taken by Alexi Lubomirski, will be released during the week.