A poor box, alms box, offertory box, or mite box is a box that is used to collect coins for charitable purposes. They can be found in most Christian churches built before the 19th century and were the main source of funds for poor relief before societies decided to organize the process and make the public authorities responsible for this.

Contemporary mite boxes are usually made of cardboard and given out to church congregations during the Lenten season. The mite boxes are collected by the church, and the donations are given to the poor. Mite boxes are popular with children because they can fill them with small change, teaching them the principle of giving alms to the poor. The Mite box promotes the spirit of contributing based on the intent to help others, and not on the monetary amount.