Emmanuelle Charpentier, who is French, and American Jennifer Doudna share the 10 million Swedish crown ($1.1 million) prize for developing the CRISPR/Cas9 tool to edit the DNA of animals, plants and microorganisms with precision.
"The ability to cut the DNA where you want has revolutionized the life sciences," Pernilla Wittung Stafshede of the Swedish Academy of Sciences told an award ceremony.
Charpentier, 51, and Doudna, 56, become the sixth and seventh women to win a Nobel for chemistry, joining Marie Curie, who won in 1911, and more recently, Frances Arnold, in 2018.
It is the first time since 1964, when Britain's Dorothy Crowfoot Hodgkin alone won the award, that no men are among the chemistry prize winners.
Charpentier, of the Max Planck Unit for the Science of Pathogens, told journalists in Berlin she was "extremely emotional and extremely moved" by the award, which came as a complete surprise even though she had been tipped as contender.