Ruth Aaronson Bari (November 17, 1917 – August 25, 2005) was an American mathematician known for her work in graph theory and algebraic homomorphisms.
The daughter of Polish-Jewish immigrants to the United States, she was a professor at George Washington University beginning in 1966.
She was the mother of environmental activist Judi Bari, science reporter Gina Kolata and art historian Martha Bari.