Richard Beatty Mellon (March 19, 1858 – December 1, 1933), sometimes R.B., was a banker, industrialist, and philanthropist from Pittsburgh, Pennsylvania.

They also made joint philanthropic gifts, notably several large donations to their alma mater, the University of Pittsburgh, including creation of the Mellon Institute of Industrial Research to honor their father, which is now a part of Carnegie Mellon University.

In honor of his civic efforts, the Air and Waste Management Association recognizes individuals who have made administrative, legislative, and judicial contributions to the field of pollution abatement with the Richard Beatty Mellon Award.

He and his wife, Jennie Taylor King, were the major donors to the Cathedral of Hope, the new home for the East Liberty Presbyterian Church, which they and their parents had attended.

[4] The $13.3 million in taxes paid on his estate enabled the state to meet its payroll.