The name Kaileigh is a modern English variant of the Scottish Gaelic name Cailleach, which means "old woman" or "veiled one." The name has its roots in ancient Celtic mythology, where the Cailleach was a powerful goddess associated with winter, storms, and the cycle of life and death.

In early Celtic folklore, the Cailleach was depicted as an old woman with a staff or wand, representing the harsh winter months. She was believed to bring storms and blustery weather, but her departure in spring signaled the arrival of new life and growth. The name Cailleach may also be related to the Gaelic word "caille," meaning "veil" or "hood," referring to the goddess's veiled or hooded appearance.

The name Kaileigh emerged as a modern anglicized spelling of the traditional Gaelic name Cailleach. While the name has its origins in ancient Celtic mythology, there are no known historical records or texts that specifically mention individuals named Kaileigh or Cailleach from that time period.

One of the earliest recorded instances of the name Kaileigh dates back to the late 20th century, when it began to gain popularity as a feminine given name in English-speaking countries, particularly in the United States and the United Kingdom. The spelling variation Kaileigh may have been influenced by the trend of adding unique or creative spellings to traditional names.

Throughout history, the name Cailleach has been associated with several notable individuals, although the spelling Kaileigh is relatively modern. Here are five examples:

1. Cailleach Bheur (dates unknown): In Scottish folklore, Cailleach Bheur was a powerful winter goddess who was believed to bring storms and harsh weather. She was often depicted as an old woman with a staff or wand.

2. Cailleach Beara (dates unknown): In Irish mythology, Cailleach Beara was a goddess associated with the Beara Peninsula in County Cork. She was believed to be the personification of the land itself and was revered for her power over the natural world.

3. Cailleach Mor (dates unknown): In Scottish and Irish folklore, Cailleach Mor was a legendary figure who was said to have created many of the mountains and geographical features of the Scottish Highlands and Ireland.

4. Caitlín Ní Uallacháin (1566-1600): Caitlín Ní Uallacháin was an Irish noblewoman and poet who lived during the 16th century. She is renowned for her poetry, which often celebrated the beauty of nature and the Irish landscape.

5. Caileigh Filmer-Diggory (born 1985): Caileigh Filmer-Diggory is a contemporary Australian actress and model, best known for her roles in television series such as "All Saints" and "Home and Away."