Cyrus Abda (C. A.) Dolph (September 27, 1840 – June 22, 1914) was a businessman in Portland, Oregon, United States. He was a promoter and counselor of various financial and railway enterprises of the Pacific Northwest of the United States. He was born September 27, 1840, on a farm near Havana, Chemung, now Schuyler County, New York. He was called Abda in honor of one of his forefathers, , who was born in Bolton, Massachusetts, in 1740, and served with distinction in the Revolutionary war, as did his brother Charles.