Sarah Cordelia Mellon Scaife (1903–1965) was an American heiress, philanthropist, and Republican Party donor, renowned for her role in the Mellon family legacy. Born on December 10, 1903, in Pittsburgh, Pennsylvania, she was the daughter of banking magnate Richard Beatty Mellon and Jennie Taylor Mellon, making her the niece of industrialist and former U.S. Treasury Secretary Andrew W. Mellon. She was the sister of Richard King Mellon and married Alan Magee Scaife, with whom she had a son, Richard Mellon Scaife, who later became a prominent newspaper publisher and conservative philanthropist. Growing up in the affluent Mellon family environment in Pittsburgh, Sarah inherited a significant portion of the family's banking and industrial fortune, which stemmed from the Mellon National Bank and various industrial enterprises.

Sarah dedicated her wealth and influence to philanthropy, establishing the Sarah Scaife Foundation in 1941 to support public policy initiatives, educational causes, and charitable organizations. A committed Republican donor, she contributed to political campaigns and conservative causes, reflecting the family's traditional values. In recognition of her civic contributions, she received an honorary Doctor of Humane Letters degree from the University of Pittsburgh during its 1955 commencement ceremony. Her foundation played a pivotal role in funding cultural institutions, medical research, and policy think tanks, particularly in the Pittsburgh region and beyond.

Sarah Mellon Scaife passed away on December 28, 1965, leaving a lasting impact through her foundation, which continued under her son's stewardship to support center-right public policy organizations. Her life exemplified the intersection of old money, philanthropy, and political influence in mid-20th-century America, shaping networks of conservative giving that persist today.