Stephen Power Farish was born in Mayersville, Mississippi. He attended the Sewanee Military Academy and the University of the South, both in Sewanee, Tennessee.
He worked in the cotton business and as an oil field roughneck before becoming a partner in the firm of Blaffer and Farish in 1908. During World War I he enlisted at Fort Sam Houston and graduated as a second lieutenant from the US Army School of Military Aeronautics at Ohio State University.
From 1916-1922 he was in charge of one of the major divisions of Humble Oil & Refining Co. He left Humble to form the partnership of Farish, Watts and Collins of which he was president until it was sold in 1945. Farish next joined Reed Roller Bit Co., then a relatively small manufacturer of oil field supplies. He retired from Reed in 1957, but remained as a director until 1960.
He served the University of Houston as both a regent and a governor from 1937-1962.