The 15 February 2003 anti-war protest was a coordinated day of protests across the world against the imminent invasion of Iraq. The war was justified on the pretext of alleged weapons of mass destruction, thus, the protests were also regarding the illogical idea of going to war as a disarmament strategy.

Millions of people protested in approximately 800 cities around the world. According to BBC News, between six and ten million people took part in protests in up to sixty countries over the weekend of the 15th and 16th; other estimates range from eight million to thirty million.

The biggest protests took place in Europe. The protest in Rome involved around 3 million people and is listed in the 2004 Guinness Book of World Records as the largest anti-war rally in history.