Farren was born in Cambridge in April 1892. He was educated at the Perse School, Cambridge, and at Trinity College, Cambridge, where he studied mathematics.

He was in charge of aerodynamic experiment and design, Royal Aircraft Factory, 1915-18, becoming Head of their Aerodynamics department. In 1918 he joined Armstrong Whitworth Aircraft, but returned to Cambridge in 1920 as lecturer in aeronautics and engineering, becoming a fellow of Trinity College in 1933. From 1922-31 he also lectured at the Royal College of Science.

In 1937 he was appointed to the Air Ministry as Deputy Director of Scientific Research, working as Deputy Director Research and Development (1939-40) and worked in the new Ministry of Aircraft Production as Director of Technical Development (1940-41).

Between 1941 and 1946 he returned to Farnborough to become director of the then Royal Aircraft Establishment (RAE). He subsequently served as technical director of Blackburn Aircraft Company from 1946-47, technical director of AV Rose and Co from 1947-61, technical director of Hawker Siddeley Nuclear Power Company from 1956-61, and as a director of Hawker Siddeley Aviation from 1959-61. He retired in 1961, although he continued to work as a consultant for Hawker Siddeley until 1970.

He was appointed MBE in 1918, CB in 1943, was knighted in 1952, and elected as an FRS in 1945. He was later awarded an honorary DSc by Manchester University.

He was President of the Royal Aeronautical Society in 1953/4, received its gold medal in 1956 and became an honorary fellow of the Society in 1959. He died in July 1970.