Good was born in Panorama City, Los Angeles, California. Her mother, Tyra Wardlow-Doyle, worked as Good's manager into her teens, and her father, Leondis "Leon" Good, is an LAPD police officer. According to Good, her maternal grandmother is "Jewish and African, so I guess that would be considered Creole. My mother's father was Cherokee and something else. My dad's mother's Puerto Rican and black, and his father was from Barbados." Good was raised in Canyon Country (now known as Santa Clarita), California, with her three siblings. She began her acting career around the age of four. In the early stages of her career, Good started out doing work as an extra on television shows such as Doogie Howser, M.D. and Amen. When she was thirteen, Good was cast in her first film, the 1995 hit Friday. Good first began to gain recognition for her performance as troubled teen Cisely Batiste in Kasi Lemmons' critically acclaimed 1997 film Eve's Bayou, which earned Good two award nominations, including her first NAACP Image Award nomination.
Good currently lives in Studio City, California. Although she was not raised in the church, Good is a Christian and a very spiritual person, and has stated in numerous interviews that she will not do roles that she feels might "disappoint God". She explained in an interview that Jesus tops her hero list and the last book she read was the Bible.
In early April 2012, Good became engaged to boyfriend DeVon Franklin, an executive for Columbia Pictures and a Seventh-day Adventist preacher. The two began dating in 2011 and were married on June 16, 2012, in Malibu, California.