Todd played main role in the Broadway comedy play Carry Me Back to Morningside Heights directed by Sidney Poitier. She later appeared opposite Poitier, who was her mentor early in her career, in films such as The Lost Man (1969), They Call Me Mister Tibbs! (1970), Brother John (1971). and A Piece of the Action (1977). On television, she was regular cast member on the daytime soap opera, Love of Life, from 1968 to 1970, and in 1977 the educational show The Write Channel on PBS. Todd was nominated an NAACP Image Award for her performance in the critically acclaimed PBS production of Six Characters in Search of an Author (1976). She received her second NAACP Image Award nomination for her role in the ABC miniseries, Roots.

Todd had the female leading roles in films Moving (1988) opposite Richard Pryor, and Lean on Me (1989) with Morgan Freeman. She was married to film producer-director Kris Keiser. Their son, Malik Smith, died on March 20, 1989 at age 18 after being severely beaten at a teen youth center (no alcohol served or allowed) while on spring break. She did not appear regularly on the screen during the 1990s, and returned to acting in 2002, with a recurring role in the HBO series, Six Feet Under. In 2004, she appeared as Don Cheadle's character's mother in the critically acclaimed film, Crash. In 2007, she reunited with Morgan Freeman (who co-starred with her in Lean On Me), in the comedy-drama film, The Bucket List. Todd also had supporting roles in the independent films The Lena Baker Story (2008) and I Will Follow (2011). On television, Todd guest starred on House, The Closer and Grey's Anatomy, and, in 2012, had the recurring role in the NBC daytime soap opera, Days of Our Lives as Celeste Perrault, the mother of Lexie Carver (Renée Jones).