Angela O'Neill was born in Oakland, California on March 13, 1965 to Emmett Michael O'Neill (1932-2011) and Carmen "Cara" O'Neill née Foruria, both school teachers. She was raised in Calistoga, California, took the GED at age 16, then transferred to UCLA's theater program as an actress where she studied film and theater technical arts as well. She graduated summa cum laude from UCLA at 19 and began auditioning. Her acting debut was a starring role in the Roger Corman movie Sorority House Massacre (1986). She studied acting at the Beverly Hills Playhouse while represented by the Gersch Agency. Angela moved to South Africa and starred in a series of action movies and traveled in Africa, Europe, and Australia for 5 years. Returning to Los Angeles in 1995, she began working in production to support her acting career. She worked for Jerry Moss as a PA on two shows and learned how to do Props.