Born in Vicksburg, Mississippi, Richards was graduated from Dillard University and spent three years as an apprentice at the San Diego Community Theater in the late 1940s, early 50s, before moving to NYC to pursue an acting career. The soft-spoken, kindly-faced actress was cast as a grandmother (at the age of 30) in the Off-Broadway production of "Take a Giant Step" in 1956 and understudied Claudia McNeil in the lead role of Lena Younger in the 1959 Broadway production of "A Raisin in the Sun". (Richards eventually played the role in L.A. in 1968 and again at the Yale Repertory Theatre in 1983). She garnered critical acclaim for her starring performance in "The Amen Corner" (1965) which earned her a Theater World Award and a Tony nomination as Best Actress. During the 70s, Richards appeared in two plays she had written "One Is a Crowd" (1970) and "A Black Woman Speaks" (1975) and also developed a one-woman show "An Evening with Beah Richards".

While Richards made her film debut in the feature version of "Take a Giant Step" (1959), she did not recreate her stage role. For the movie, she was cast not as the hero's grandmother, but as his mother. Subsequently Richards recreated her stage roles of Viney in "The Miracle Worker" (1962) and Idella in "Gone Are the Days!/Purlie Victorious" (1963). 1967 offered Richards three prime roles: as Robert Hooks' white-haired mother in Otto Preminger's "Hurry Sundown"; as the town abortionist in Norman Jewison's Oscar-winning "In the Heat of the Night"; and "Guess Who's Coming to Dinner?". Despite her Oscar nomination, Richards was cast only sporadically in features in the 70s and 80s, mostly in small roles that hardly tapped her abilities (e.g., "Mahogany" 1975 and "Homer and Eddie" 1989). In 1998, she made a one-shot return to the big screen as Baby Suggs, the mother-in-law of Oprah Winfrey's Sethe, in "Beloved".

The small screen has proven more hospitable to Richards' talents. She began making guest appearances in the 60s and has been featured in regular or recurring roles in five series. She succeeded Lillian Randolph as Bill Cosby's mother during the 1970-71 season of "The Bill Cosby Show" (NBC) and was Aunt Ethel on "Sanford and Son" (NBC, 1972). Other series credits include a recurring role as a voodoo priestess on "Beauty and the Beast" (CBS, 1987-89) and as Markie Post's childhood nursemaid in "Hearts Afire" (CBS, 1992). Richards won an Emmy as Best Guest Performer in an acclaimed episode of "Frank's Place" (CBS, 1987) as the wife of a man whose death in a car accident isn't what it first appears. She subsequently played the mother of a paranoid schizophrenic Diana Ross in Ross' TV movie debut, "Out of Darkness" (ABC, 1994). Richards also was amongst the players in the 1990 "American Playhouse" production of the stage play "Zora Is My Name!" dramatizing the life and work of writer and cultural anthropologist Zora Neale Hurston. In 2000, shortly before her untimely death, Richards picked up a second Emmy Award for her moving guest appearance as an elderly woman whose daughter was moving to end her mother's new marriage in an episode of the ABC drama series "The Practice".