Boyd Barrett helped to organise mass protests against the war in Iraq in 2003. He addressed the Dublin leg of the 20 March 2003 International Day of Action. He said that it was "almost certain" that any war would lead to between 50,000 and 100,000 deaths. He said "the complicity of the Irish Government in this murderous war through providing facilities for the US military at Shannon airport" was "an absolute disgrace" and urged people to protest in their thousands "to show this carnage is not being mounted in our names". In 2009, he supported the pro-democracy protests in Iran.