Oatley was born in Bristol in 1863, and after working as an apprentice to the architect Thomas Dashwood, he became a junior draughtsman for the local firm Godwin and Crisp, at the age of 16. Oatley became Henry Crisp's partner aged only 26, when Godwin left the firm, and at the same time married Edith Lawrence.
Work for Bristol University
His major break came with his appointment as Architect to the University of Bristol. One of his first projects, and probably the major one of his career, was to design the Wills Memorial Building to be a landmark for the new university, in 1912. He produced an imposing design in the Perpendicular Gothic style. Building was begun in 1915, and after being delayed through World War I, it was finally completed in 1925. Oatley was knighted the same year in recognition of his work. His other work for the University included the H.H. Wills Physics Department, started in 1926 and opened in 1930; Wills Hall, a student hall of residence in Stoke Bishop in 1925; and Manor Hall, a student hall of residence in Clifton in.
Oatley's keen Christian faith is reflected in the large amount of work he did for local churches. He designed the mission hall of St Anne's in Greenbank, Bristol Baptist College, St Edyth's in Sea Mills and Sea Mills Methodist Church. Other projects included work on St. Mary Redcliffe church and the New Room, John Wesley's original Methodist chapel. Oatley was also involved in raising financial support for various Christian causes.
Other work
Local Bristol firms also benefited from Oatley's designing talents, such as the J. S. Fry & Sons chocolate company, for whom he designed several factories, and the Bristol Wagon Works. Oatley had worked on his own throughout his most prolific period, only joined by his brother-in-law George C. Lawrence in 1926. Ralph H. Brentnall joined the company in 1947, but it was only three years later that Oatley died in 1950. He had been based at 12 Great George Street, Bristol for the majority of his career. Oatley lived at an ‘arts and crafts’ house, Barton Rocks, in Somerset, which he had built early in the 20th century. The house remained in his family until 1976.