Casey started her swimming journey with a YMCA team when she was 11. Fanz quickly found her love for the sport and joined a local USA Swimming team, Poseidon Swimming in Richmond, Virginia. Fanz swam for Poseidon from the ages of 12-18. During that time she was an Olympic Trials Qualifier in the 50 and 100 Free and was a member of the NCSA All-American Team that traveled and competed in Ireland after winning the 50 free at the 2014 NCSA Nationals. Fanz was the captain of the Poseidon Senior Women's team and holds 17 club records. She was the 4-time defending state champion in the 50 free, having won consecutive state titles and had been named twice to the First Team All-Metro Richmond Times Dispatch. Upon graduating high school and starting her college career, Fanz made an immediate impact for the Cardinals both on relays and in sprint freestyle events. During her time as a Louisville Cardinal, Casey was an ACC Champion, NCAA All-American, 4-time NCAA Qualifier, and Olympic Trials Qualifier. In her final year as a Cardinal, Casey swam the third-fastest times in school history in the 50 free (21.89) and the 100 free (47.87), qualifying individually for her fourth NCAA Championships. Due to COVID-19 cancelling the final meet of her college-swimming career and Olympic Trials being postponed, Fanz was presented with a unique opportunity to keep swimming another year. Fanz is currently training for Tokyo 2021 with Louisville’s Pro Group and is excited to continue swimming professionally.