Protests against the Iraq war take place in over 600 cities worldwide. It is estimated that between eight million and 30 million people participate, making this the largest peace demonstration in history.

On 15 February 2003, a coordinated day of protests was held across the world in which people in more than 600 cities expressed opposition to the imminent Iraq War. It was part of a series of protests and political events that had begun in 2002 and continued as the invasion, war, and occupation took place. The day was described by social movement researchers as "the largest protest event in human history".