Samuel Benjamin Harris is an American philosopher, neuroscientist, author, and podcast host. His work touches on a range of topics, including rationality, religion, ethics, free will, neuroscience, meditation, psychedelics, philosophy of mind, politics, terrorism, and artificial intelligence. Harris came to prominence for his criticism of religion, and is known as one of the "Four Horsemen" of New Atheism, along with Richard Dawkins, Christopher Hitchens, and Daniel Dennett.

Criticism of religion involves criticism of the validity, concept, or ideas of religion. Historical records of criticism of religion go back to at least 5th century BCE in ancient Greece, in Athens specifically, with Diagoras "the Atheist" of Melos. In ancient Rome, an early known example is Lucretius' De rerum natura from the 1st century BCE.