Kaylyn is a modern American combination of Kay and Lyn, which American parents put together in the 1980s alongside Kaylin, Kailyn and Kaylynn; Kay goes back to Katherine and so to the Greek katharos, "pure", and Lyn is a short form of Lynn or Linda. The name was most popular around 2000, when it stood at number 589; it left the top 1000 in the 2010s and has slipped from number 1272 in 2015 to number 2525 among girls' names in 2025.