The Duke, wearing his military uniform, saluted and paid his respects to the fallen, before walking back in the small crowd.
Meghan then followed, also planting her cross and lowering her head as sign of respect.
This was the first time Meghan had joined Harry at the Field of Remembrance.
Camilla, Duchess of Cornwall had also been scheduled to attend the event, however Prince Charles's wife was forced to pull out after her doctor "ordered" her to cancel her engagements.
According to Clarence House, Camilla is suffering from a chest infection.
In a statement, the spokeswoman said: “The Duchess of Cornwall has been told by her doctor to cancel her engagements owing to a chest infection which has got progressively worse over the last few days.”
The Field of Remembrance was opened by the Duke of Edinburgh, Prince Philip, and Harry joined his grandfather for several years at this solemn event.
Following the visit to the Field of Remembrance, Meghan and Harry visited the memorial plots for regimental and other associations.
There, they met veterans - including people who took part in the D-Day landing.
Meghan and Harry thanked them for their service, while Harry was also seen shaking their hands.
Other Remembrance Services attended by the Royal Family this year include:
Saturday, November 9 - The Queen and members of the Royal Family will attend the annual Royal British Legion Festival of Remembrance at the Royal Albert Hall.
Sunday, November 10 - The Queen and members of the Royal Family will attend the annual Remembrance Day Service at The Cenotaph on Remembrance Sunday.
Monday, November 11 - The Duke of Kent will attend The National Memorial Arboretum Armistice Day Service in Staffordshire.