A penny is a coin or a unit of currency in various countries. Borrowed from the Carolingian denarius, it is usually the smallest denomination within a currency system. Presently, it is the formal name of the British penny (abbr. p) and the de facto name of the American one-cent coin (abbr. ¢) as well as the informal Irish designation of the 1 cent euro coin (abbr. c). Due to inflation, pennies have lost virtually all their purchasing power and are often viewed as an expensive burden to merchants, banks, government mints and the public in general.

The cent, the United States of America one-cent coin, often called the "penny", is a unit of currency equaling one one-hundredth of a United States of America dollar. It has been the lowest face-value physical unit of U.S. currency since the abolition of the half-cent in 1857. The first U.S. cent was produced in 1787, and the cent has been issued primarily as a copper or copper-plated coin throughout its history. Due to inflation, pennies have lost virtually all their purchasing power and are often viewed as an expensive burden to businesses, banks, government and the public in general.