Roberts was born in Biloxi, Mississippi. His parents, Betty Lou (née Bredemus) and Walter Grady Roberts, one-time actors and playwrights, met while performing theatrical productions for the armed forces. They later co-founded the Atlanta Actors and Writers Workshop in Atlanta, Georgia off of Juniper Street in Midtown. Roberts' mother filed for divorce in 1971 and it was finalized early in 1972. His younger siblings, Julia Roberts (from whom he was estranged until 2004) and Lisa Roberts Gillan, are also actors. His mother married Michael Motes and had daughter Nancy Motes in 1976. Roberts is of English, Scottish, Irish, Welsh, German, and Swedish ancestry. Roberts was raised in Atlanta, Georgia. He studied at Henry W. Grady High School.