Kaitlyn, of Irish origin, is derived from the ancient Celtic name 'Caitlín', meaning 'pure' or 'virginal'. It gained popularity in the United States during the 20th century, peaking in the late 1980s and early 1990s. Kaitlyn is often associated with the spelling variants Caitlin and Katie.
The name Kaitlyn gained popularity steadily over the years, with a notable spike in usage from 2004 onwards, reaching a peak of 35 births that year. However, it appears to have declined since then, with fewer than 10 births per year from 2009 onwards.