Afro-Eurasia or less commonly Afrasia or Eurafrasia is the term used to describe the largest landmass on earth. It may be defined as a supercontinent, consisting of Africa and Eurasia (further divided into Asia and Europe). The constituent landmasses encompass 84,980,532 square kilometers and have a population of approximately 6 billion people, or roughly 85% of the world population. It is also known as the Old World, as opposed to the Americas, which are known as the New World.

The mainland of Afro-Eurasia has been referred to as the World Island, a term coined by Sir Halford John Mackinder in The Geographical Pivot of History. (The term excludes non-mainland islands and archipelagos.) It was the original scope of the word "continent".

Africa is expected to collide with Europe over 600,000 years from now, when the straits of Gibraltar close. When this happens, the Mediterranean Sea will be isolated from the Atlantic Ocean. Over 50 million years from now the Mediterranean is expected to disappear, creating new mountain ranges.