Robert Maclay Widney (December 23, 1838 – November 14, 1929) was an American lawyer, judge, and a founding father of The University of Southern California.
He was born in Piqua, Ohio. He was the older brother of Dr. Joseph Widney, second president of the University of Southern California, and the nephew of Robert Samuel Maclay, a pioneer missionary to China; and Charles Maclay, later a state senator for California.
Maclay left Ohio in September 1855 and spent two years hunting and trapping on the great plains and in the Rocky Mountains, arriving at last in California in September 1857. He studied at the University of the Pacific (then located in Santa Clara) from 1858 to 1862. He was admitted to the bar in 1865, and moved to Los Angeles in 1867. In 1871, he was named a judge of the Court of California for Los Angeles and San Bernardino Counties. He was a founder of the Los Angeles Chamber of Commerce (established in 1873). In 1874 he began the first rail transit company in Los Angeles, building a horsecar line from The Plaza to 6th and Pearl (now Figueroa Street) Streets.
Los Angeles was a frontier town in the early 1870s, when a group of public-spirited citizens led by Judge Robert Maclay Widney first dreamed of establishing a university in the region. It took nearly a decade for this vision to become a reality, but in 1879 Widney formed a board of trustees and secured a donation of 308 lots of land from three prominent members of the community — Ozro W. Childs, a Protestant horticulturist; former California governor John G. Downey, an Irish-Catholic pharmacist and businessman; and Isaias W. Hellman, a German-Jewish banker and philanthropist. The gift provided land for a campus as well as a source of endowment, the seeds of financial support for the nascent institution.
Robert M. Widney is interred in Angelus-Rosedale Cemetery, Los Angeles.