Pewter (also known as "antique silver") is a metal alloy, traditionally between 85 and 96 percent tin, and the rest copper and/or lead. There were three grades of pewter: Fine, for eating ware, with 96 percent tin, and 4 percent copper; Trifle, also for eating and drinking utensils but duller in appearance, with essentially 92 percent tin, 4 percent copper, and up to 4 percent lead; and Lay or Ley metal, not for eating or drinking utensils, which could contain up to 15 percent lead. Modern pewter mixes the tin with copper, antimony and/or bismuth, as opposed to lead.

Physically, pewter is a bright, shiny metal that is very similar in appearance to silver. Like silver, pewter will also oxidize to a dull gray over time if left untreated. Pewter is a very malleable alloy, being soft enough to carve with hand tools, and it also takes good impressions from punches or presses. Some types of pewter pieces, such as candlesticks, would be lathed. Pewter has a low melting point, and duplication by casting will give excellent results.

Use of pewter was common from the Middle Ages up until the various developments in glass-making during the 18th and 19th centuries. Mass production of glass products has seen glass universally replace pewter in day-to-day life. Pewter artifacts continue to be produced, mainly as decorative or specialist items. Royal Selangor Pewter is one of the world's largest producers of pewter artifacts.

A pewter is also the colloquial name for any pewter-made container, especially a pewter tankard. Tankards are certainly the most common pewter artifacts, although the metal is also used for plates, cutlery and jewellery.