Greene was born in Jacksonville, Florida, and is the daughter of Michele, who works in insurance, and Joe Greene, a U.S. Marine who now owns his own concrete business. She grew up in Middleburg and Jacksonville, and went to University Christian School before transferring to Wolfson High School when she was in tenth grade. She moved to Los Angeles, California, at the age of 17 to pursue an acting career. Greene has an older brother named Joe, who still resides in Jacksonville with his parents.
Greene is good friends with her Twilight co-stars, particularly Kellan Lutz and Jackson Rathbone whom she knew before filming of the series began
