Green was born in Houston, Texas, to Gerald and Brenda Green. He has two sisters, Delonya and Tenika, and a brother, Garlon, who played college basketball at TCU and professional basketball overseas. When he was 11 years old, Green lost a significant portion of his right ring finger after he severely injured it while trying to dunk on a makeshift rim. He attended J. Frank Dobie High School for two years but was cut from his high school basketball team as both a freshman and sophomore. He then transferred to Gulf Shores Academy in Houston. During his senior year, Green averaged 33 points, 12 rebounds, seven assists and three blocked shots per game and was named a McDonald's All-American. He posted a game-high 24 points in the 2005 McDonald's All-American Game and won the McDonald's All-American Slam Dunk Contest. Green helped rescue people and deliver supplies to those in need after Hurricane Harvey struck Houston in August of 2017. Learn more about Green by following him on Twitter (@GgreenJr25) and on Instagram (@g.green14).