The United Nations Children's Fund (or UNICEF) was created by the United Nations General Assembly on December 11, 1946, to provide emergency food and healthcare to children in countries that had been devastated by World War II. In 1953, UNICEF became a permanent part of the United Nations System and its name was shortened from the original United Nations International Children's Emergency Fund but it has continued to be known by the popular acronym based on this old name. Headquartered in New York City, UNICEF provides long-term humanitarian and developmental assistance to children and mothers in developing countries.

A voluntarily funded agency, UNICEF relies on contributions from governments and private donors. Its programs emphasize developing community-level services to promote the health and well-being of children. UNICEF was awarded the Nobel Peace Prize in 1965 and Prince of Asturias Award of Concord in 2006. In the United States, Canada and some other countries, UNICEF is known for its "Trick-Or-Treat for UNICEF" program in which children collect money for UNICEF from the houses they trick-or-treat at on Halloween night, sometimes instead of candy.