Jewellery (pronounced /ˈdʒuːəlri/ or /ˈdʒuːələri/) or jewelry (see American and British English spelling differences) is a form of personal adornment, manifesting itself as necklaces, rings, brooches, earrings and bracelets. Jewellery may be made from any material, usually gemstones, precious metals or shells. Factors affecting the choice of materials include cultural differences and the availability of the materials. Jewellery may be appreciated because of its material properties, its patterns or for meaningful symbols. Jewellery differs from other items of personal adornment in that it besides looking appealing, it often has no other purpose. Items such as belts and handbags are considered to be accessories rather than jewellery.

The word jewellery is derived from the word jewel, which was Anglicised from the Old French "jouel" circa the 13th century. Further tracing leads back to the Latin word "jocale", meaning plaything. Jewellery is one of the oldest forms of body adornment; recently-found 100,000 year-old beads made from Nassarius shells are thought to be the oldest known jewellery.

Jewellery is sometimes regarded as a way of storing wealth and might also posses some minimal functionality, such as holding a garment together or keeping hair in place. It has from very early times been regarded as a form of personal adornment. The first pieces of jewellery were made from natural materials, such as bone, animal teeth, shell, wood and carved stone. Some jewellery throughout the ages may have specifically been as an indication of a social group. More exotic jewellery is often for wealthier people, with its rarity increasing its value. Due to its personal nature and its indication of social class, some cultures established traditions of burying the dead with their jewellery.

Jewellery has been made to adorn nearly every body part, from hairpins to toe rings and many more types of jewellery. While high-quality jewellery is made with gemstones and precious metals, such as silver or gold, there is also a growing demand for art jewellery where design and creativity is prized above material value. In addition, there is the less costly costume jewellery, made from lower value materials and mass-produced. Other variations include wire sculpture (wrap) jewellery, using anything from base metal wire with rock tumbled stone to precious metals and precious gemstones.