The name Kaylea is a modern variation of the Scottish name Cailean, which is a Gaelic form of the English name Colin. The name Cailean itself is derived from the Old Gaelic word "caillen," meaning "bright-headed" or "young dog."

The earliest recorded use of the name Kaylea can be traced back to the late 20th century, likely emerging as a feminized form of the male name Cailean. While the name Cailean has a long history in Scotland, the specific spelling of Kaylea is a relatively new invention.

One of the earliest known individuals with the name Kaylea was Kaylea Langan, a Canadian ice hockey player born in 1990. Another notable figure is Kaylea Duffield, an Australian actress born in 1999, known for her roles in television series like "The Saddle Club" and "Mustangs FC."

In literature, the name Kaylea appears in the fantasy novel series "The Unicorn Chronicles" by Bruce Coville, where it is the name of one of the main characters, a young girl with a special connection to unicorns.

While not a historically common name, Kaylea has gained popularity in recent decades, particularly in English-speaking countries. Some other individuals who have borne this name include Kaylea Cross, a Canadian author of romantic suspense novels, and Kaylea Arnett, an American actress and model.

It is worth noting that the name Kaylea is primarily a modern invention, and its usage and popularity may have been influenced by its similarity to other popular names like Kayla, Kaylee, and Haley.