Ariana Gilley was born on June 4, 2003 in Indiana to Michael and Christina Gilley. She has two older sisters, Taylor and Makayla and a younger brother, Anthony. Ariana is an honor student at Roncalli Life-Preparatory High School and she will graduate from high school in 2021. When she has time outside of gymnastics, she enjoys hanging out with her friends, running, water skiing, snow skiing and boating.

Ariana followed her older sister into gymnastics at the age of three. She started her competitive gymnastics career at Wright's American Gymnastics in Greenwood, IN. As a level 8 gymnast in 2014, Ariana finished fifth on floor exercise with a 9.475 at the State Championships and qualified to the Region 5 Championships.

Ariana competed level 9 the next few seasons. In 2015, Ariana qualified to the State Championships. At the 2016 Region 5 Championships, she scored a 9.350 on floor exercise as a specialist due to a minor injury. Following her 2016 season, Ariana moved to The Flip Zone in Plainfield, IN. In 2017, Ariana's final level 9 season, she placed seventh in the all-around, first on vault and third on uneven bars at the State Championships. At the Region 5 Championships, she placed seventh in the all-around, second on uneven bars and fourth on floor exercise. She qualified to the Level 9 Eastern Nationals in Lansing, MI, finishing tenth in the all-around, second on floor exercise and sixth on uneven bars. Ariana helped Region 5 to win the team title.

As a first-year level 10 gymnast in 2018, Ariana finished sixth in the all-around with a 36.500 at the State Championships. She qualified to the Region 5 Championships but was unable to compete due to extreme illness. In 2019, Ariana placed second in the all-around with a 37.500 and second on balance beam at the State Championships. At the Region 5 Championships, she finished in the top ten in the all-around and first on balance beam. In May 2019, Ariana moved to Jaycie Phelps Athletic Center (JPAC) in Greenfield, IN.

In 2020, Ariana qualified to the Level 10 State Championships but was unable to compete due to COVID-19 pandemic.

Ariana trains 24 hours per week at Jaycie Phelps Athletic Center (JPAC) in Greenfield, IN under coach Dave Marcus. Her long-term goal is to compete for a college gymnastics team.