Over two million people participated in worldwide strikes to protest climate change across 2,400 locations worldwide.

The September 2019 climate strikes, also known as the Global Week for Future, were a series of international strikes and protests to demand action be taken to address climate change, which took place from 20 to 27 September 2019. The strikes' key dates were 20 September, which was three days before the United Nations Climate Summit, and 27 September. The protests took place across 4,500 locations in 150 countries. The event stemmed from the Fridays for Future school strike for climate movement, inspired by Swedish climate activist Greta Thunberg. The Guardian reported that roughly 6 million people participated in the events, whilst 350.org – a group that organised many of the protests – claim that 7.6 million people participated.

September 27 is the 270th day of the year in the Gregorian calendar; 95 days remain until the end of the year.