Meanwhile Prince Harry changed from his military uniform into a navy suit. William was the fourth successive generation of the monarchy to become an RAF pilot. They will go on to a garden party at the Glencairn House - the United Kingdom embassy in Dublin.
On the accessories front, Meghan carried a black Givenchy clutch, Birks earrings, and Aquazzura shoes.
However, there was one aspect of their outfits which were nearly identical - their shoes. The Duchess also accessorised with gloves, which she could be seen carrying alongside a clutch, all in ideal tonal coordination.
Meghan and Harry join the Queen at RAF centenary service
The Duke and Duchess of Cambridge were last seen less than 24 hours ago for the christening of their youngest son Prince Louis . Catherine's parents, her sister and brother-in-law Pippa and James Matthews and her brother James will also be in attendance.
The newlyweds have a series of engagements lined up over the next 48 hours.
This evening, Meghan and Harry will attend a garden party at the British Ambassador's residence at Glencairn.
They will also visit DogPatch Labs, a co-working space for technology start-ups, where they will meet young people taking part in workshops and female tech entrepreneurs.
Kensington Palace said the couple were "looking forward to learning more about Ireland's history and experiencing its rich culture, as well as meeting the people who are shaping the country's future".