Creationism is the religious belief that nature, and aspects such as the universe, Earth, life, and humans, originated with supernatural acts of divine creation, and is often pseudoscientific. In its broadest sense, creationism includes various religious views, which differ in their acceptance or rejection of modern scientific concepts, such as evolution, that describe the origin and development of natural phenomena.

The term creationism most often refers to belief in special creation: the claim that the universe and lifeforms were created as they exist today by divine action, and that the only true explanations are those which are compatible with a Christian fundamentalist literal interpretation of the creation myth found in the Bible's Genesis creation narrative. Since the 1970s, the most common form of this has been Young Earth creationism which posits special creation of the universe and lifeforms within the last 10,000 years on the basis of flood geology, and promotes pseudoscientific creation science. From the 18th century onward, Old Earth creationism accepted geological time harmonized with Genesis through gap or day-age theory, while supporting anti-evolution. Modern old-Earth creationists support progressive creationism and continue to reject evolutionary explanations. Following political controversy, creation science was reformulated as intelligent design and neo-creationism.

Mainline Protestants and the Catholic Church reconcile modern science with their faith in Creation through forms of theistic evolution which hold that God purposefully created through the laws of nature, and accept evolution. Some groups call their belief evolutionary creationism. Less prominently, there are also members of the Islamic and Hindu faiths who are creationists.