Born in Columbus, Ind., Dec. 17, 1891, son of William Henry and Adelia May (Newsom) Donner and grandson of Frederick and Mary Jane (Johnson) Donner. His grandfather came to this country from Germany in 1847 and settled in Columbus.
After receiving his preliminary education at Shady Side Academy, Pittsburgh, Pa., and Phillips Academy, Andover, Mass., Robert Donner attended Yale University in 1912-1913.
He began his career in the steel industry in 1915, when he joined the New York Steel Co., Buffalo, an enterprise that was purchased by his father in that year. The business was incorporated as the Donner Steel Co., Inc., in 1918, and the son served it as vice-president and a director until 1930, when it was sold to the Republic Steel Corp.
During the next decade Donner was in business for his own account, and in 1940 he founded Donner Estates, Inc., Philadelphia, Pa., an investment firm that became known as the Donner Corp. in 1947. He remained a director of that enterprise from the time of its inception until 1957, when he retired from all business activity.
At other times he was the vice-president of the Pennsylvania East Side Land Co. and a director of Rittenhouse Plaza Apartments, Inc., Penn-Pitt Supply Co., and Penn-Pitt Coal & Coke Co., all in Philadelphia. From 1946 to 1949 Donner served as president and a director of the Donner Foundation, Inc., Philadelphia, an endowment fund, and from the latter year until the close of his life he was chairman of the board. The fund was established in memory of his brother, Joseph W. Donner, by their father in 1932 and began operations with $2 million to provide funds for cancer research.
He was married Sept. 7, 1928, to Margaret, daughter of John Croil Hunter of Fargo, N.Dak., a merchant, and had two children: Robert and Margaret Hunter, who married William M. Spencer, Jr.