The gathering took place near a beach where the Australian and New Zealand Army Corps, or Anzacs, first landed at Gallipoli at dawn on April 25, 1915.
As the sun began to rise, the ceremony in northwest Turkey began with a mournful Maori lament, setting the tone for a solemn observance that included prayers and the laying of wreaths.
NZ Prime Minister Christopher Luxon spoke of the human cost of war and the importance of preventing conflict in the future.
"Anzac troops came ashore here shoulder-to-shoulder with their brothers from half a world away. Some anticipated adventure far from home. But as the sun rose and the shadows drained from the gullies, it was not adventure that greeted them, but horror," Luxon said.
"It would be a disservice to those whose valour we remember, if we forget the real lesson of this campaign: that we should do all we can - all we can - to prevent anything like it happening again," he said.
The campaign, part of a British-led effort to defeat the Ottoman Empire, ultimately failed, resulting in tens of thousands of deaths on both sides during the eight-month conflict.
It aimed to secure a naval route from the Mediterranean Sea to Istanbul through the Dardanelles, and knock the Ottomans out of the war.
As in previous years, travellers from Australia and New Zealand camped overnight at the site, which is now known as Anzac Cove, to attend the dawn service.
Among them was 61-year-old Glen Lancaster, from Melbourne, Australia, whose great-uncle took part in the Gallipoli landings.
Lancaster expressed both "excitement and sadness for what happened. (I'm) amazed at how those men must have felt coming up the beach".
Anne, the sister of King Charles III, and president of the Commonwealth Graves Commission, read from letters some soldiers wrote home and paid tribute to the soldiers on both sides of the conflict.
"This was the start of an eight-months-long campaign, costing and changing the lives of tens of thousands of Australians (and) New Zealand, British, French and Ottoman soldiers," she said.
She also paid respect to Australian and New Zealand troops involved in various conflicts and peacekeeping missions since Gallipoli.
On Thursday, Anne attended separate ceremonies honouring British and French soldiers.
The battle helped forge Australia and New Zealand's national identities as well as friendship with their former adversary, Turkey.
The campaign is an important part of Turkish history.
Modern Turkey's founder, Mustafa Kemal Ataturk rose to prominence as commander of the Turkish forces at Gallipoli, went on to lead Turkey's War of Independence and ultimately found the Turkish Republic.
