Keegan is an Irish name of uncertain origin, possibly derived from Ó Seanáin meaning "descendant of Seanán," a diminutive form of Seán which means "old" or "wise." It has been used as both a surname and given name over time, with some influence from the English name Kevin. Today, Keegan is typically considered a male name but can also be used for females, and it gained popularity in the late 20th century.