Meghan worked with the College of Arms in London to come up with design, which was later approved by the Queen.
The shield’s right-hand side has two golden stripes on a blue background – representing California’s famous sunny climate and the Pacific Ocean.
Three quills represent the power of words and communication.
The left half of the shield features the quartered British Royal Arms.
Golden poppies, California’s state flower, are in the grass at the base of the shield, along with wintersweet, which grows at her new home of Kensington Palace.
The golden lion on the left relates to Prince Harry, while the Duchess of Sussex chose a songbird.
Thomas Woodcock, the Garter King of Arms and Senior Herald in England, said: “The Duchess of Sussex took a great interest in the design.
“Good heraldic design is nearly always simple and the Arms of The Duchess of Sussex stand well beside the historic beauty of the quartered British Royal Arms.”