A metalsmith or simply smith is a craftsperson fashioning useful items (for example, tools, kitchenware, tableware, jewelry, armor and weapons) out of various metals. Smithing is one of the oldest metalworking occupations. Shaping metal with a hammer (forging) is the archetypical component of smithing. Often the hammering is done while the metal is hot, having been heated in a forge. Smithing can also involve the other aspects of metalworking, such as refining metals from their ores (traditionally done by smelting), casting it into shapes (founding), and filing to shape and size.

The prevalence of metalworking in the culture of recent centuries has led Smith and its equivalents in various languages to be a common occupational surname (German Schmidt or Schmied, Portuguese Ferreiro, Ferreira, French Lefèvre, Spanish Herrero, Italian Fabbri, Ferrari, Ferrero, Ukrainian Koval etc.). As a suffix, -smith connotes a meaning of a specialized craftsperson—for example, wordsmith and tunesmith are nouns synonymous with writer or songwriter, respectively.