Giambrone was born in Michigan, to a family of Italian and German descent. He then moved with his family to Park Ridge, Illinois.
He attended Lincoln Middle School, and Maine South High School. He now splits his time between Los Angeles and Park Ridge.
He took up acting at the age of 9, starring in television commercials for McDonald's and Friendly's Restaurants among others.
In 2014, Giambrone joined the voice cast of the animated series Clarence, which aired on Cartoon Network, providing the voice of Jeff, a friend of the title character. He also made an appearance in R.L. Stine's The Haunting Hour, and provided the voice of a bull terrier named Russell in the DVD film Russell Madness.