The rally, organised by the IF campaign, was held to highlight the scandal of 870 million people going without enough food every day. Scots campaigners at the rally included supporters of SCIAF, the Scottish Catholic development agency.
The UK Government has been hosting the G8 meeting of some of the world's most powerful leaders in Enniskillen yesterday and today.
SCIAF and other IF campaigners are calling upon the leaders to stop large corporations avoiding paying tax on the profits they make in the poorest countries - lost revenue they say could be spent on food and development.
They also want action to protect poor farmers from land grabs and make sure that the agricultural land in the poorest countries is actually used to grow food, rather than biofuels for cars.
John Sharp, SCIAF's Campaigns Officer said "We're delighted to see so many Scots make the journey to the Big IF rally in Belfast.
"The G8 leaders meeting this week have to listen to the roar of the people who are demanding action to end the scandal of global hunger.
"They must seize this opportunity to stamp out corporate tax avoidance which robs developing nations of billions of pounds and halt land grabs which lead to poor farmers being evicted from their land in the name of profits from foreign corporations."