Gianna Lenczner was born on November 7, 2003 in Wisconsin to Daniel and Christine Lenczner. She has an older brother, Brandon, a younger sister, Aspen and a dog named Lacey. Aspen is also a gymnast at Salto Gymnastics. Gianna is an honor student at Oak Creek East Middle School and she will graduate from high school in 2022. She is in the top 6% of her class.

Gianna asked her mom if she could do gymnastics when she was five years old. She started her gymnastics career at Altius Gymnastics Academy in Franklin, WI. As a level 4 gymnast in 2011, Gianna placed second in the all-around and second on vault and floor exercise at the State Championships. She moved up to level 5 for the 2012 season where she placed first on floor exercise, third on balance beam and fourth in the all-around. Gianna skipped level 6 and tested out of level 7 before moving up to level 8 for the 2014 season. At the Level 8 State Championships, Gianna earned a bronze medal on balance beam with a 9.500. She qualified to the Region 4 Championships.

Following Gianna's 2014 season, she moved to Salto Gymnastics in Waukesha, WI. Gianna continued competing level 8 in 2015. At the State Championships, she placed fourth in the all-around and fourth on balance beam. She qualified to the Region 4 Championships where she finished sixth in the all-around, second on floor exercise and fourth on balance beam.

As a first-year level 9 gymnast in 2016, Gianna won the floor exercise title with a 9.400 at the Region 4 Championships. In 2017, she placed fifth in the all-around and first on floor exercise with a 9.475 at the Level 9 State Championships. At the Region 4 Championships, Gianna finished first on balance beam, fourth on floor exercise and eighth in the all-around. She qualified to the Level 9 Western Nationals in Boise, ID.

Gianna moved up to level 10 for the 2018 season. She placed third in the all-around and third on vault, balance beam and floor exercise at the State Championships. At the Region 4 Championships, Gianna finished eighth in the all-around and fifth on vault. She was the first alternate for the Junior Olympic Nationals. In 2019, Gianna was unable to compete in the post-season due to an injury. In 2020, Gianna qualified to the Level 10 State Championship but was unable to compete due to COVID-19 pandemic. Her season was highlighted with an all-around win at Excalibur Cup and Northern Lights Classic Event Finalist on floor exercise with a 9.625.

Gianna trains 24 hours per week at Salto Gymnastics in Waukesha, WI under coaches Vitali Rudnitski, Kristen Kremer, Brittany Solberg and Juliet Holden. Gianna is working hard to become a successful level 10 gymnast where she hopes to qualify to the Junior Olympic Nationals every year. Her long-term goal is to compete for a Division I college gymnastics team.