Kayliee is of modern origin, first appearing in the late 20th century. It's believed to be a blend of popular names like Kayla and Kyle, reflecting the trend towards unique and personalized monikers during that period. The name gained popularity in English-speaking countries, particularly in the United States, Canada, and Australia.
"The name Kayliee had a peak of popularity in 2010 and 2014 with 10 births each year. After a decline in the mid-2010s, it saw a slight resurgence in 2017 and 2021, but overall, its usage has been decreasing since 2015."