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 applied to the University of Florida in 2015. He achieved some social media fame thanks to his sister on Instagram with more than 20,000 followers.
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.