The couple will be joined by the Duchess of Cornwall, who is patron of the Poppy Factory in south-west London where remembrance poppies are made.
The Field of Remembrance has been organised by the Poppy Factory and held in the grounds of Westminster Abbey since November 1928, when only two Remembrance tribute crosses were planted.
There are now approximately 70,000 crosses produced by the factory team each year which are planted on more than 360 plots for regimental and other associations.
In the run-up to Remembrance Sunday, members of the monarchy are attending a series of events commemorating those who paid the ultimate sacrifice, culminating in the service at the Cenotaph, where the Queen and senior royals will gather to pay their respects.
During their visit, Harry, Meghan and Camilla will each lay a cross of remembrance and tour the plots, where they will meet veterans from all areas of the armed forces who have served in past campaigns and more recent conflicts.