A thimble is a protective shield worn on the finger or thumb.

Thimbles are most usually made from metal, leather, rubber, wood, glass or china. Early thimbles were sometimes made from bone, horn or ivory.

Originally thimbles were used solely for pushing a needle through fabric or leather as it was being sewn. However they have since gained many other uses. In the 1800s they were used to measure spirits (hence the phrase "just a thimbleful"). Women of the night used them in the practice of thimble-knocking where they would tap on a window to announce their presence. Thimble-knocking also refers to the practice of Victorian schoolmistresses who would tap on the heads of unruly pupils with dames thimbles. During the First World War silver thimbles were collected from "those who had nothing to give" by the British government and melted down to buy hospital equipment. In the 1930s and 40s red-topped thimbles were used for advertising. Leaving a sandalwood thimble in a fabric stores helps to keep moths away. Thimbles have also been used as love-tokens and to commemorate important events. A miniature thimble is one of the tokens in the game of Monopoly.

People who collect thimbles are known as digitabulists.