Tiller was a four-year letterwinner at Carthage (Mo.) High School where she helped the Tigers to three district finals including a title effort during her senior season. Carthage also qualified for the state tournament in 2016. She finished her prep career with 983 kills and established school records in kills, total blocks and blocks per game. Tiller played club with Ozark Juniors in Fayetteville. In addition to her volleyball accolades, she played a season of basketball at CHS.
Kiley is the daughter of Ron and Rhonda Tiller, and has three siblings, Gage, Katey and Gannon. Her father was a football student-athlete at Pitt State University. Tiller is planning to major in kinesiology exercise science at Arkansas.