The planet Mercury was named by ancient Romans after their messenger god and the god of travelers, Mercury. They believed that their messenger god, Mercury, had wings on his shoes and could fly quickly from one place to another.
CoolCosmos states that the Romans were familiar with seven bright celestial bodies. These objects were the sun, moon and five planets (including Mercury), which were visible to the naked eye. The planet Mercury moves around the Sun quickly, because it is closer to the Sun than the other planets. Therefore, the Romans named it after their fast-moving messenger god, Mercury, according to NASA.