The surname "O'Malley" is of Irish origin, derived from the Gaelic name "Ó Maolmhuire," which means "descendant of Maolmhuire." The name is associated with the ancient Gaelic nobility of Connacht, a province in western Ireland. O'Malley families historically held significant land and power, particularly in County Mayo. O'Malley is also linked to the famous figure Gráinne Mhaol, or "Gráinne the Bald," a 16th-century pirate and chieftain known for her leadership and resistance against English rule. Today, the surname is common among those of Irish descent and can be found in various countries, especially in the United States.