Jack Iscaro was originally born in Germany, but moved to Olney, Maryland at the age of three. Iscaro played his first game of rugby at 10 years old, inspired by his father who is a former Italian national team player. Iscaro was a captain at Gonzaga College High School where he won two highschool club national championships as well as having played in a plethora of USA Junior National Team competitions. He went on to play rugby at University of California - Berkeley where he also won two National Championships and was named a Collegiate All-American in 2019.
Iscaro was selected to play for Old Glory DC in 2020, and was named on the USA Falcons squad in 2022. He played for his first USA cap against Hong Kong in 2022.