Anglicized form of Irish Ó Ríagáin meaning 'little king' or 'impulsive one.'
Reagan began as an Irish surname, usually traced to Ó Riagáin, meaning “descendant of Riagán.” The root is often connected to the Irish rí, “king,” which gives the name a faintly regal undertone, though surname histories are often more layered than a single neat translation suggests. Like many Irish surnames, Reagan entered given-name use through the long modern habit of turning family names into first names, especially in the United States.
Its cultural profile changed dramatically in the late 20th century because of Ronald Reagan, the 40th president of the United States. That association made the name feel political, presidential, and distinctly American for many people, even though its roots are Irish. At the same time, Reagan has also been used for girls as well as boys, and in recent decades it has leaned strongly feminine in American naming.
That shift reflects a broader trend in contemporary English naming: surnames with sharp consonants and tailored sounds often become stylish unisex or girl names. There is also a literary echo in Shakespeare through Regan, one of the daughters in King Lear, though that is a different spelling and history. As a result, Reagan sits at an interesting crossroads, carrying Irish ancestry, modern surname-chic appeal, and a powerful overlay of public memory.