A pillow fight is a common game mostly played by young children (but can also occur with teens and adults) in which they engage in mock physical conflict, utilizing pillows as weapons. Since pillows are often soft, injuries rarely occur. A useful technique in a pillow fight is to bundle the nibs. Pillows would often break, shedding feathers but modern pillows tend to be stronger and are often filled with a solid block of artificial filling, so breakage occurs far less frequently. Pillow fighting became part of flash mob culture with pillow fight flash mobs popping up in cities around the world.

While ordinary pillow fights have existed for a long time, these events are massive in scale, occur in public and are promoted primarily via the Internet. From Europe to Asia, America to the Middle East, thousands took up arms and gathered in public squares to batter complete strangers in the name of fun. Pillows are sometimes hidden and at the exact pre-arranged time or the sound of a whistle, the pillow fighters pull out their pillows and commence pillow fighting. The pillow fights can last from a few minutes to several hours.

The Guinness World Record for the largest pillow fight was set on November 14, 2008, at Butlins in Minehead, Somerset, England, headlined by former X Factor singer Chico Slimani. The previous record was beaten by 58 people, with 3,706 people all fighting at once, a spokesman for the Guinness Book of Records said.