Oreo is a brand of cookie usually consisting of two chocolate cookies with a sweet crème filling, marketed as "Chocolate Sandwich Cookie".
Introduced in 1912, Oreo is the bestselling cookie in the United States. As of 2018, the version sold in the U.S. is made by the Nabisco division of Mondelez International.
Oreos are available in over one hundred different countries; in some countries, such as the United Kingdom, they are referred to as Oreo biscuits.
Many different varieties of Oreo cookies have been produced, and limited edition runs have become popular in the 21st century.