<P> Mary Margaret `` Peggy '' Wood ( February 9 , 1892 -- March 18 , 1978 ) was an American actress of stage , film , and television . She is best remembered for her performance as the title character in the CBS television series Mama ( 1949 -- 1957 ) , for which she was nominated for a Primetime Emmy Award for Outstanding Lead Actress in a Drama Series ; her starring role as Naomi , Ruth 's mother - in - law , in The Story of Ruth ( 1960 ) ; and her final screen appearance as Mother Abbess in The Sound of Music ( 1965 ) , for which she was nominated for an Academy Award and a Golden Globe Award . </P>
who played the reverend mother in sound of music
Mary Margaret `` Peggy '' Wood