Rosaleen is an Irish female first name. It is an Anglicized version of the Irish name Róisín, the diminutive of "rose" in the Irish language; it therefore means "little rose". It has use in Ireland since the 16th century, possibly popularised by Rosaline in Shakespeare's Romeo and Juliet.
The name featured in "Dark Rosaleen" by James Clarence Mangan, a patriotic poem disguised as a love song, in a time when nationalistic expression was outlawed in Ireland. Thus the name is a poetic symbol of Ireland.