At 11am, the only sound was the heavy rain beating on the ground as those in attendance joined with others across the UK in a two-minute silence.
It was broken by the band of the Royal Irish Regiment who played as representatives from Northern Ireland, the rest of the UK and the Republic laid wreaths.
Representatives of the police and Armed Services also placed wreaths at the cenotaph to pay tribute to their fallen colleagues.
The Secretary of State for Northern Ireland, Theresa Villiers MP, laid a wreath on behalf of the Government in Belfast where she was accompanied by First Minister Peter Robinson, and the Irish Minister for Foreign Affairs, Charlie Flanagan.
"Today's service was made particularly poignant as we approach 2016 and the centenary of the Somme which will have special resonance in Northern Ireland. We owe all the men and women who have served in the armed forces over the past hundred years a deep debt of gratitude," she said.
Mr Flanagan was attending the ceremony for the second time to lay a laurel wreath on behalf of the Irish government.
"Men and women from across the island and from all traditions were involved in the First World War," he said.
"Today's ceremony is an important opportunity to reflect on their lives and to recognise the impact that this conflict had on countless thousands of families."
More than 200,000 Irish-born soldiers served in the British Army and Navy from 1914 to 1918.
Thousands also joined Britain during the Second World War.
Also present was Deputy Mayor Guy Spence. He said: "This morning's service was very poignant. Many people came out despite the weather to pay tribute to those who had defended our country.
"It was particularly great that Charlie Flanagan was with us so that all parts of the islands were united. It was great to see that unity and it will go a long way in ensuring remembering the fallen is done respectfully and with dignity."
Sinn Fein Lord Mayor Arder Carson did not attend the ceremony.
In Enniskillen, Taoiseach Enda Kenny attended the service, 28 years to the day after the IRA bombed the Remembrance Day service there.
Eleven people who had gathered to pay respects were killed and dozens more were injured in the no-warning blast in 1987 just minutes before the event was due to start.
Mr Kenny became the first Taoiseach to attend a Remembrance Day service in Northern Ireland when he took part in commemorations at Enniskillen in 2012. Every year since he has been invited to return to the Co Fermanagh town, and every year he has accepted the invitation.
He stood alongside Finance Minister Arlene Foster and Fermanagh and South Tyrone MP Tom Elliott to remember those who died in the area.
In Londonderry, veterans and dignitaries were led by the Lord Lieutenant, Dr Angela Garvey, as they laid wreaths at the war memorial in the Diamond.
Among them were Derry City and Strabane District Council Deputy Mayor Thomas Kerrigan of the SDLP, PSNI Superintendent Mark McEwan and the SDLP's Gerard Diver. Sinn Fein Mayor Elisha McCallion did not attend.
Services were also held in Holywood, Lisburn, Newry, Hillsborough, Armagh and many other towns and villages across Northern Ireland.