A demonym ( /ˈdɛmənɪm/), also referred to as a gentilic, is a name for a resident of a locality. A demonym is usually—though not always—derived from the name of the locality; thus, the demonym for the people of Britain is British, and the demonym for the people of Italy is Italian, yet the one used in the English language for the people of the Netherlands is Dutch (in Dutch Nederland/Nederlander).

The word demonym comes from the Greek word for "populace" (δῆμος demos) with the suffix for "name" (-onym).

National Geographic Magazine attributes this term to Merriam-Webster editor Paul Dickson. It was subsequently popularized in this sense in 1997 by Dickson in his book Labels for Locals. Dickson himself attributed the term to George H. Scheetz in What Do You Call a Person From...? A Dictionary of Resident Names (the first edition of Labels for Locals). The term first appeared in Names' Names: A Descriptive and Prescriptive Onymicon by George H. Scheetz. The term is foreshadowed in demonymic, which the Oxford English Dictionary defines as the name of an Athenian citizen according to the deme to which he belonged, with first usage traced to 1893.