Haddon was a painter and illustrator. He illustrated the following books:
Browne, Edith A., Peeps at Many Lands: Spain, with twelve full-page illustrations in colour by Trevor Haddon and Edgar T. A. Wigram, London: Adam & Charles Black, 1910
Calvert, Albert Frederick, Granada Present and Bygone, (illustrations by Trevor Haddon), J. M. Dent, London, 1908
Calvert, Albert Frederick, Southern Spain: Painted By Trevor Haddon, A. & C. Black, Ltd., London, 1908
Gould, Baring, A Book of the Rhine from Cleve to Mainz. With eight Illustrations in Colour by Trevor Haddon, London, Methuen 1906
Nye, G.H.F, Our Island Home (8 illustrations by Trevor Haddon), Bemrose & Sons, Limited, London, c. 1898
Okey, Thomas, The Old Venetian Palaces and Old Venetian Folk. With Fifty Coloured and Other Illustrations by Trevor Haddon, London. J. M. Dent & Co. 1907
Thirlmere, Rowland, Letters from Catalonia and other parts of Spain (illustrations by Trevor Haddon), Hutchinson & Co., London, 1905
Personal life
Although he lived primarily in London and Cambridge, Haddon traveled to Rome, Madrid, Venice, California, South America, Hawaii, and Asia. He died in Cambridge on December 13, 1941 at age 77.
