James Ryan was born on 6 December 1891 in Wexford. He was educated in Wexford and qualified in medicine at University College Dublin. As a medical student he joined the Irish Volunteers and served as medical officer in the DPO during the Easter Rising in 1916. He was imprisoned but released in 1917 after an amnesty. In 1918 he became a Sinn Féin MP for Wexford. He supported the Republican side after the Treaty debates. He was elected TD for Wexford in 1923. In 1926 he became a founder-member of Fianna Fáil.
In 1932 he became Minister for Agriculture when Fianna Fáil came to power. He held that post until 1947 when he became the first Minister for Health and Social Welfare. Between 1954 and 1957 he served as Minister for Finance. He transformed the department to a dynamic one of economic affairs. He worked extensively with Dr TK Whitaker in laying the groundwork for the first Programme for Economic Expansion (1959). Ryan retired from politics in 1965 to hid farm in Wicklow.
Dr James Ryan died on 25 September 1970.