Iranians took part in the demonstrations in 770 cities and towns across the country.
Muslims of 80 countries are also attending similar rallies.
Iranian Parliament Speaker Ali Larijani would deliver speech in the demonstration.
Over 800 Iranian correspondents and photographers and 100 foreign reporters are covering the event.
In August 1979, the late founder of the Islamic Republic Ayatollah Khomeini declared the last Friday of Ramadan as the International Quds Day, calling on Muslims across the world to mark the annual occasion by holding street rallies.
Millions of people around the world take to the streets on the day in a show of support for the people of Palestine, demanding an end to the Israeli occupation of the Palestinian land, ISNA reports.