World Thinking Day was first created in 1926 at the fourth Girl Guide/Girl Scout International Conference, held at Girl Scouts of the USA’s Camp Edith Macy (now called Edith Macy Conference Center). Participants of the Conference decided that there should be a special day when Girl Guides and Girl Scouts all around the world think of each other and give thanks and appreciation for their “sister” Girl Guides. The delegates chose February 22 as the date for Thinking Day because it was the mutual birthday of Lord Baden-Powell, founder of the Girl Guide/Girl Scout movement, and his wife Lady Olave, who served as World Chief Guide.

In 1932, at the seventh World Conference, held in Poland, a Belgian delegate suggested that since birthdays usually involve presents, girls could show their appreciation and friendship on Thinking Day not only by extending warm wishes but by offering a voluntary contribution to the World Association. This is how the World Association’s Thinking Day Fund began.
To emphasize the global aspect of Thinking Day, members at the 30th World Conference, held in Ireland in 1999, changed the name Thinking Day to World Thinking Day.