In several cultures, a middle name is a portion of a personal name that is written between the person's first given name and their surname.A middle name is often abbreviated and is then called middle initial or just initial.

A person may be given a middle name regardless of whether it is necessary to distinguish them from other people with the same given name and surname. In cultures where a given name is expected to precede the surname, additional names are likely to be placed after the given name and before the surname, and thus called middle names.

The use of multiple middle names has been somewhat impeded recently by the increased use of computer databases that occasionally allow for only a single middle name or more commonly a middle initial in storing personal records, effectively preventing people with multiple middle names from being listed in such databases under their full name. This is worsened by longer compound names, like María del Pilar Pereyra or María de las Nieves García Fernández.

Since 1905, "middle name" has also developed a figure of speech and meaning a notable or outstanding attribute of a person, as in the phrase "discretion is my middle name." It is a recurring trope in entertainment.