The Duke of Cambridge, 39, laid a wreath at the Cenotaph on behalf of his grandmother, the Queen, on Monday morning, before attending the Westminster service.
Anzac Day, which falls on April 25, observes the anniversary of the start of the First World War Gallipoli landings.
The doomed 1915 campaign saw thousands of Anzac troops, or the Australian and New Zealand Army Corps, die after Allied forces attacked the Turkish Peninsula.
The aim was to taken control of the Dardanelles straits, a critical route towards Russia and the Black Sea.
But the campaign failed to gain ground, and the forces withdrew from the area eight months later.
The “Anzac spirit” is celebrated on April 25 as a show of endurance and discipline.
It is marked with a national day of remembrance in Australia and New Zealand.
The High Commissioners of Australia and New Zealand will address the congregation during the service at the Abbey, as will the Dean of Westminster.