But the bride may wear two dresses, as the Duchess of Cambridge did – one to the church ceremony and another to the evening reception.
Meghan turned to the Australian duo behind British label Ralph & Russo for one of the gowns she wore in her official engagement photos.
Tamara Ralph and Michael Russo are renowned for their full-on Hollywood glamour, jewel-encrusted couture designs.
American label Oscar de la Renta would be a nod by LA-born Meghan to her home country.
Oscar de la Renta crafted the wedding dresses of Amal Clooney and actress Kate Bosworth and is known for its classic glamour.
Laura Kim and Fernando Garcia are its creative directors.
Erdem has been a bookmakers’ favourite for some time.
Founded in 2005 by Erdem Moralioglu, the brand is known for its sweeping dresses and floral prints.
Canadian-born, with a Turkish father, the London-based designer counts the Duchess of Cambridge, former US first lady Michelle Obama, style doyenne Alexa Chung and actress Keira Knightley among his clients.
Knightley is particularly a fan of the pockets he puts on her gowns, allowing her to feel more relaxed as she tucks her hands away on the red carpet.
'The Erdem woman has remained the same, she has never been concerned with being cool,' Moralioglu once said.
Burberry’s Christopher Bailey has been cited as the perfect choice by designer Henry Holland.
Bailey, the former chief creative officer, is leaving the British heritage brand at the end of the year.
Holland said: 'I would be quite excited if it was Christopher Bailey’s final bow for Burberry.'
Jenny Packham, known for her intricate romantic, beaded bridal gowns, has also been suggested.
Described by Vogue as 'one of the red carpet’s go-to designers for dazzling feminine glamour', Packham is already a favourite with the Duchess of Cambridge.
Angelina Jolie, Keira Knightley, Beyonce, Jennifer Lopez and Cameron Diaz are among her fans.
She is the sister of UK broadcaster and naturalist Chris Packham.
If the American star wanted to pick one of Britain’s leading couturiers, she could choose Phillipa Lepley.
Her style is classic, romantic, understated elegance and trademarks are hand-made body sculpting corsetry, beading and embroidery.
Famously discreet, she is a self-confessed perfectionist who believes 'a wedding dress should be timeless and flattering above all else'.
She designed Geri Horner’s wedding dress, as well as those of Ulrika Jonsson and Davina McCall.
At her first wedding in 2011, Meghan married film producer Trevor Engelson on a beach in Jamaica in a sleek, strapless, floor-length white dress with diamante waist detail.
This article originally appeared on the Press Association.
