Alexis Diakakis was born on May 23, 2003 in New York to Nicholas and Jeanette Diakakis. She is the youngest of four children. Her older sister, Varvara is currently a gymnast at the University of Bridgeport. Alexis is an honor student at Half Hollow Hills High West and she will graduate in 2021. During Alexis's spare time, she enjoys reading, sketching, singing, playing other sports and knitting/crocheting.

Alexis used to flip herself out of the crib and was found hanging outside on the rails. She was an early walker and known to climb. Her mom enrolled her into recreational classes when she was 18 months old to use up excess energy. She has been training under coach Tammy Marshall most of her competitive gymnastics career.

In 2014 as a level 6 gymnast, Alexis placed sixth in the all-around and third on balance beam at the State Championships. As a level 7 gymnast, she finished in the top ten in the all-around at the 2015 State Championships, third on uneven bars and in the all-around at the 2016 State Championships and fifth on balance beam at the 2016 Region 6 Championships. Alexis skipped level 8 and moved up to level 9 for the next two seasons. She qualified to Region 6 Championships in both seasons of 2017 and 2018. In 2019, Alexis placed second in the all-around and third on balance beam and floor exercise at the State Championships. She qualified to the Level 9 Eastern Nationals after finishing fourth in the all-around and third on floor exercise at the Region 6 Championships.

Alexis trains 22 hours per week at Towers Gymnastics in Holbrook, NY under coach Matt Towers. She would like like to compete for a college gymnastics team.