Butler died Friday at Northwest Hospital of head injuries suffered in fall at her home in Lake Forest Park, Wash., the Seattle Times reported Monday.
Butler's heros and heroines were often people of color and she used her fantasy worlds and creatures to tackle current issues such as intolerance, poverty and the environment, the newspaper said.
Her novels included "Kindred," "Parable of the Talents" and "Fledgling," which came out last fall.
Butler won a $299,000 genius grant from the MacArthur Foundation in 1995 -- the only science fiction writer to ever have won the award -- and "Parable of the Talents" took science fiction's highest prize, the Nebula Award, in 2000.
Fellow sci-fi writer and friend, Steven Barnes, told The Times he considers Butler "the most important science-fiction writer since Mary Shelley."
Her friend and mentor, Harlan Ellison, said Butler overcame dual obstacles of being female and black in a field dominated by white males to become the one of the best-known African-American sci-fi writers.
Butler is survived by two aunts and several cousins.