The couple’s May 19 wedding at St. George's Chapel will be a public affair, with TV cameras allowed inside the wedding ceremony and more than 2,000 members of the public invited to watch the carriage procession outside after the wedding.
Here are all the details you need to know for Harry and Markle's wedding day.
How you can watch the wedding
In addition to the cameras inside St. George’s Chapel for the ceremony, the order of the service will be published online on Saturday so the public can follow along.
Cameras will also line the carriage procession route in Windsor.
ABC News and "GMA" will have special coverage from 5 to 10 a.m. ET live from Windsor, England.
"GMA" co-anchor Robin Roberts and "World News Tonight" anchor David Muir, along with a team of reporters and royal experts, will have live updates and colorful commentary from Windsor and London.
You don't need a TV either. The five hours of special coverage will be available to stream on ABC News' digital platforms including, ABCNews.com and GoodMorningAmerica.com, mobile apps, social platforms and over-the-top (OTT) services.
Ready to throw a royal wedding viewing party? Click HERE for the ultimate guide.
Prince Charles will walk Markle down the aisle
Prince Charles will walk Markle from the quire, the area of St. George’s Chapel where the clergy and choir sit, to Harry. The procession in the nave, the central part of the church, will include Markle, the Dean of Windsor and Markle’s bridesmaids and page boys.
Markle originally asked her dad, Thomas Markle Sr., to walk her down the aisle but chose her soon-to-be father-in-law after her father became unable to attend the wedding.
Markle, 36, confirmed in a statement that her dad, who lives in Mexico, will not attend the wedding due to health concerns.
Who's who in the wedding party
Markle will not have a maid of honor by her side, as she did not want to single out one of her close circle of friends, sources told ABC News.
She will though have bridesmaids and page boys, all children, by her side at her wedding.
Also joining Charlotte and George in the wedding party will be the three children of Markle's best friend, entrepreneur and style adviser Jessica Mulroney.
Ivy Mulroney, 4, will serve as a bridesmaid, while her older brothers, 7-year-old twins Brian and John Mulroney, will join George as page boys.
Also serving as a page boy will be Jasper Dyer, the 6-year-old son of Harry's mentor and close friend, Capt. Mark Dyer.
Joining Charlotte and Ivy as bridesmaids will be two of Harry's goddaughters -- 3-year-old Florence van Cutsem and 2-year-old Zalie Warren -- and two of Markle's goddaughters, 7-year-old Rylan Litt and her 6-year-old sister, Remi Litt.
William will serve as best man on May 19, just as Harry served as best man at William and Kate's wedding in 2011.
Who will design Markle's dress?
A top contender for designing Markle's gown is the design duo behind Ralph & Russo.
Australian-born designers Tamara Ralph and Michael Russo drew the spotlight when Markle chose their jaw-dropping $75,000 gown for her engagement photos with Harry last December.
Other possibilities for the coveted design assignment have included Christopher Bailey, the visionary behind the iconic British brand Burberry, British designer Stella McCartney, Canadian designer Erdem Moralioglu, and Roland Mouret, a close friend of Markle's.
British designer Victoria Beckham, whose sweater Markle wore in her engagement photos with Harry, has denied she is creating Markle's dress.
"Sadly not, but I'm sure she will look incredible in whatever she wears," Beckham said on the April 12th episode of CBS' "The Late Late Show With James Corden."
Markle had her first fitting with the unnamed designer in January at Kensington Palace, royal reporter Omid Scobie told ABC News at the time.
Markle's mom's important role
Markle’s mom, Doria Ragland, is expected to be the only member of her family attending the wedding. She will accompany Markle by car from her overnight location to Windsor Castle on the day of the wedding.
Ragland, a Los Angeles-based yoga instructor and social worker, has spent the days before the wedding meeting Harry’s royal relatives and Harry and Markle’s closest friends in the U.K.
Princess Diana's sentimental influence
Princess Diana's memory will be kept alive at the wedding through the presence of her three siblings.
Lady Jane Fellowes, Diana's sister, will deliver the reading at the wedding.
Both Markle and Harry have said how important it is that Harry's late mother be included in their wedding.
"I think she would be over the moon, jumping up and down, so excited for me," Harry said when his engagement to Markle was announced. "But then, as I said, [she] would've probably been best friends with Meghan."
Markle's engagement ring features two diamonds from Diana's personal collection.
"The little diamonds on either side are from my mother's jewelry collection to make sure that she's with us on this crazy journey together," Harry said in November.
Location, location, location
Harry and Markle will wed at St. George’s Chapel on the grounds of Windsor Castle, about 22 miles outside of London.
The chapel, which can seat 800 people, is where Harry was baptized in 1984. It is also where Harry's father, Prince Charles, and Camilla, Duchess of Cornwall, held a service of prayer and dedication at the chapel in 2005 following their marriage at Guild Hall.
The last royal wedding to be held at St. George's Chapel was a decade ago, when Peter Phillips wed Autumn Kelly in May 2008, according to the chapel's website.
Where Harry and Markle will stay
The couple will stay at separate hotels on the eve of their wedding.
Harry will be joined by his best man, William, at the Dorchester Collection's Coworth Park. Markle and her mother will stay at Cliveden House Hotel, on the National Trust's Cliveden Estate, according to Kensington Palace.
Wedding day lineup
The wedding will begin at noon local time, 7 a.m., ET, on May 19.
The Right Rev. David Conner, the dean of Windsor, will conduct the wedding service. The Most Rev. Justin Welby, the archbishop of Canterbury, who baptized and confirmed Markle, will officiate when the couple takes their marriage vows.
The Most Reverend Michael Bruce Curry, the 27th Presiding Bishop and Primate of The Episcopal Church, will give the address at the wedding.
Harry and William will arrive by foot, entering through the chapel's west steps and walking past the crowds gathered outside the chapel on their way in.
Markle will also enter the chapel through the west steps, joined by some of the bridesmaids and page boys.
Following the hour-long wedding ceremony, the couple will meet in the chapel's Horseshoe Cloisterwith with 200 representatives of charities for which Harry has served as patron.
Harry and Markle plan to undertake a carriage procession that will start at St. George's Chapel, leave Windsor Castle via Castle Hill, continue along High Street through Windsor Town before returning to Windsor Castle on a route called the Long Walk.
They will be waved off on their carriage ride by members of the Royal Family. The guests at the wedding service will observe the sendoff of the carriage procession.
After the carriage procession, the newlyweds will attend a lunchtime reception, hosted by Queen Elizabeth, at St. George's Hall, where they will rejoin their wedding guests.
In the evening, a smaller group of 200 guests will attend a reception hosted by Harry’s father, Prince Charles, at Frogmore House.
Frogmore House, also on the grounds of Windsor Castle, is the location Markle and Harry chose for their intimate engagement photos released by Kensington Palace in December.
Both receptions will be closed to the public but there may be a second glimpse of Markle and Harry when they depart Windsor Castle for Frogmore House in the evening.
The wedding cake's California connection
Harry and Markle selected pastry chef Claire Ptak, owner of Violet Bakery in Hackney, East London, to design their wedding cake.
Ptak, like Markle, was raised in California before moving to London. Her bakery is notable for using seasonal and organic ingredients in cakes.
Ptak is creating a lemon elderflower cake with buttercream icing and fresh flowers as decorations, according to Kensington Palace.
The choice of a lemon elderflower cake is a departure from the royal tradition of serving British fruit cake on the wedding day.
William and Kate had two cakes on their wedding day in 2011, a traditional eight-tier fruit cake created by chef Fiona Cairns and a chocolate biscuit cake from a beloved Buckingham Palace recipe.
See the gilded wedding invitations
Roughly 600 invitations to Harry and Markle's wedding have been issued, Kensington Palace announced in late March.
The invitations are printed in gold and black on English card using American ink, a process that some saw as a nod to Markle's American roots.
Issued “in the name of His Royal Highness The Prince of Wales," each invitation is accented with gilded edges and features The Three Feather Badge of The Prince of Wales, according to Kensington Palace. The names of invited guests were added by a calligraphy printer.
The invitations were produced by Barnard & Westwood, a London-based fine printers and bookbinders company that has been making royal invitations since 1985.
The man behind the camera
Harry and Markle have selected Alexi Lubomirski to be the official photographer at their wedding.
Lubomirski, a renowned portrait and fashion photographer, will take the official photographs at Windsor Castle following Harry and Markle's wedding at St George's Chapel.
Lubomirski is a former assistant to Mario Testino, who was a favorite photographer of Harry's mother, the late Princess Diana.
He was also selected by Harry and Markle to take their engagement photos at Frogmore House, Windsor, that were released by Kensington Palace in December.
Markle's favorite bloom in the wedding flowers
The wedding floral displays in St. George's Chapel will include white garden roses foxgloves and peonies, Markle’s favorite bloom, as well as local branches of beech, birch, and hornbeam.
Markle and Harry have chosen Philippa Craddock to design the flowers for both the church service at St. George’s Chapel and the wedding reception at St. George’s Hall hosted by Queen Elizabeth.
Craddock, based in Fulham, is one of the most notable florists in London, with clients including Kensington Palace, Hampton Court Palace, Alexander McQueen, Christian Dior, the Victoria and Albert Museum and British Vogue.
The flowers -- which will also include locally-sourced foliage from areas around Windsor Castle -- will be donated to various charities after the wedding, according to Kensington Palace.
The soundtrack of the wedding
Harry and Markle's wedding day will be illuminated by the sounds of a gospel choir, an organ, trumpets, a full orchestra, a soprano and a 19-year-old cellist who was personally asked by Markle.
"I was bowled over when Ms. Markle called me to ask if I would play during the ceremony," Sheku Kanneh-Mason said in a statement released by Kensington Palace. "And of course I immediately said yes. What a privilege to be able to play the cello at such a wonderful event. I can’t wait!”
The music during the wedding ceremony will be under the direction of St. George's Chapel's director of music, James Vivian, and will also include the choir of St. George's Chapel, according to Kensington Palace.
The entire ceremony will also be recorded live and released on Decca Records, a U.K.-based records label. The album, which will include a collector's booklet, will go on sale around the world on May 25, according to Decca Records.
Harry and Markle's horse-drawn royal carriage
The newlyweds will travel through Windsor Town and along the Long Walk in the Ascot Landau carriage.
The carriage, which will be pulled by Windsor Grey horses, is one of five Ascot Landaus used by the royal family. Two of the Ascot Landaus were used at William and Kate's 2011 wedding, including carrying Harry in his role as best man.
The most celeb-studded royal wedding to date?
Among the high-profile guests who could attend Harry and Markle's wedding are some of Markle's celebrity friends, including actress Priyanka Chopra and tennis star Serena Williams.
Former President Barack Obama and Michelle Obama will not be at the wedding at Windsor Castle, despite speculation they would attend. It is unclear whether the Obamas received an invitation but declined to avoid a political distraction.
Markle and Harry decided against inviting political leaders from the U.K. and abroad to their wedding, meaning President Donald Trump and U.K. Prime Minister Theresa May will not attend.
Markle has though invited several members of the cast of "Suits," the TV show she starred on for seven seasons, ABC News has learned. Also expected to attend the wedding ceremony is Elton John, one of Diana’s closest friends who has worked with Harry on AIDs policy.
Singers Ed Sheeran and Rihanna and members of Coldplay, who have all actively supported Harry's charitable work, could also get invites.
Spice Girls star Mel B said on a talk show in February that all five Spice Girls have been invited to Harry and Markle's wedding.
Mel B declined to comment on whether the Spice Girls would perform on the big day, saying, "You’re going to get me fired! Let’s not talk about it anymore! Let’s pretend that I never said that.”
Other members of the girl band have since indicated they will not be performing.
Prince William and Princess Kate invited Ellie Goulding to perform at their wedding reception in 2011.
Everyday people will play a role
Harry and Markle have invited 2,640 people onto the grounds of Windsor Castle to see the wedding carriage procession as it departs.
Members of the public were selected from different regions of the U.K. with a special emphasis on those who have served their community. The couple also invited 100 students from two local schools in Windsor that have a strong affiliation with Windsor Castle.
Harry and Markle also extended invitations to 200 individuals who take part in charities and organizations for which Harry serves as royal patron.
Armed Forces will play a role too
More than 250 members of the Armed Forces will provide ceremonial support at both the wedding and the carriage procession, according to the U.K. Ministry of Defense.
"Members of the Household Cavalry will form a staircase party at St George’s Chapel, Windsor Castle as part of the wedding," the statement reads. "The State Trumpeters and a Captain’s Escort from the Household Cavalry will also provide ceremonial support."
The members will come from British Armed Forces units with a “special relationship” to Harry, a veteran. Harry served two tours of duty in Afghanistan and rose to the rank of Captain during his time in the military.
Is Markle planning this all on her own?
Markle's best friend and stylist, Jessica Mulroney, is also a bridal planner and assisting Markle in the entire design and concept of the wedding party outfits and look for the reception.
Mulroney is Canada’s best-known stylist who styled Markle during her seven-season run on the TV drama "Suits," which films in Toronto.
Since Markle's engagement to Harry, Mulroney helped select the dress and coat Markle wore on the day the couple's engagement was announced in November. Mulroney was also at Markle's side advising her on the gown and sweater Markle wore for her intimate engagement photos with Harry.
Mulroney is the wife of Ben Mulroney, whose father is a former prime minister of Canada. The two are one of Canada's best-known power couples and are often considered Canadian royalty in Toronto.
Who is paying for this celebration?
Kensington Palace confirmed in a statement released after the couple’s engagement that Harry’s family would pay for the “core aspects of the wedding.”
"As was the case with the wedding of The Duke and Duchess of Cambridge, The Royal Family will pay for the core aspects of the wedding, such as the church service, the associated music, flowers, decorations, and the reception afterwards,” the statement read.
Markle is expected to pay for her wedding dress. Security costs for the wedding day will come at the expense of U.K. taxpayers.
Queen Elizabeth gives handwritten, formal consent
Buckingham Palace shared an image of the handwritten Instrument of Consent. According to the Succession to the Crown Act of 2013, the first six people in line to the throne must obtain the consent of the Queen before marrying.
A design to the left of the text on the Instrument of Consent “incorporates a red dragon, the heraldic symbol of Wales, together with the U.K.'s floral emblems -- the rose, thistle and shamrock. It also features Prince Harry’s label, including three tiny red escallops from the Spencer family arms," according to Buckingham Palace.
To the right of the text is a rose, which is the national flower of the United States, and two golden poppies, the state flower of California where Markle was born. Between the flowers is the Welsh leek, together with Harry’s label. Beneath the label are olive branches, adopted from the Great Seal of the United States. The document also incorporates the coronet for Harry.
The honeymoon will be delayed
Harry and Markle will delay their honeymoon and do a public engagement the week after the wedding.
The newlyweds will attend Prince Charles's 70th birthday patronage celebration at Buckingham Palace on May 22, just days after their wedding.
Markle and Harry will take a honeymoon sometime thereafter, before resuming a busy schedule of engagements for the rest of the year.
The couple will not do any public engagements between now and their wedding day.