World Smile Day is celebrated on the first Friday in the month of October every year. The idea of World Smile Day was coined and initiated by Harvey Ball, a commercial artist from Worcester, Massachusetts. Harvey Ball is known to have created the Smiley Face in 1963.The World's first World Smile Day was held in the year 1999 and has been held annually since.

After Harvey died in 2001, the "Harvey Ball World Smile Foundation" was created to honour his name and memory. The slogan of the Smile Foundation is "improving this world, one smile at a time." The Foundation continues as the official sponsor of World Smile Day each year.

The message of the World Smile Day 2010 is "Do an act of kindness. Help one person smile."