Older brother of transgender activist Jazz Jennings, creator of the YouTube series I Am Jazz. Griffen can be seen alongside his sister in the TLC series I Am Jazz.
He and his family grew up in Southern Florida. He competed in cross country in high school.
He attended the University of Florida.
He has a twin brother named Sander and an older sister named Ari. His parents are Jeanette and Greg Jennings.
He has been very protective of his sibling Jazz Jennings on social media.