Trained at the Royal Academy of Dramatic Art (RADA) in London, England.
Her father, Henry E.B. Okonedo, was Nigerian. Her mother, Joan Allman, is from a Jewish family (they immigrated from Poland and Russia to England).
Gave birth to her only child -- a daughter, Aoife Okonedo Martin -- in June 1997, at age 28. Child's father is her former boyfriend, Eoin Martin.
Attended and graduated from the University of Cambridge in Cambridge, England.
Invited to join the Academy of Motion Picture Arts and Sciences (AMPAS) in 2005.
In 2005, Okonedo became the first black actress since Angela Bassett in 1994 to receive an NAACP Image Award nomination for the same role in which she was nominated for an Oscar. Previous Oscar nominees Marianne Jean-Baptiste, Halle Berry and Queen Latifah were not nominated by the NAACP for the same roles.
She was awarded the OBE (Officer of the Order of the British Empire) in the 2010 Queen's Birthday Honours List for her services to drama.
She won the 2014 Tony Award for Best Featured Actress in a Play, appearing on Broadway opposite Denzel Washington in "A Raisin in the Sun". She later said that one of the best things about her Broadway debut was that she got to say she was "Denzel Washington's wife".
She was awarded the CBE (Commander of the Order of the British Empire) in the 2019 Queen's New Years Honours List for her services to Drama. She is an actress in East Sussex, England.