Walter Knight Shirley, 11th Earl Ferrers (5 June 1864 – 2 February 1937) was a British architect and nobleman.
Born at Christ Church, Oxford, where his father was a professor and canon, Shirley was the second but only surviving son of Rev. Walter Waddington Shirley (d. 1866) and his wife Philippa Knight.
Educated at Winchester College and New College, Oxford, whence he took a B.A. in 1887, Shirley entered the profession of architecture and was articled to Basil Champneys. Part of the Arts and Crafts Movement, he was an active member of the Society for the Protection of Ancient Buildings and the Art Workers Guild. He designed a large addition to 35 Victoria Road, Kensington in 1896. Shirley's obituary described him as "a most conscientious architect...over-exacting, if anything, in his own work".
On 9 July 1890, Shirley married Mary Jane Moon (d. 10 Jan 1944), daughter of the barrister Robert Moon and the sister of Edward Robert Pacy Moon, by whom he had five children:
In 1912, Shirley succeeded his childless fourth cousin as Earl Ferrers, and largely retired from architecture to tend the family estates. He died at the family seat of Staunton Harold Hall in 1937.