English architect, designer, and a pioneer of the English Arts and Crafts movement.

After studying at the Ruskin School of Drawing and Fine Art, Oxford, and traveling with John Ruskin (Ruskin, John) to Italy, Mackmurdo set up practice in London. Known best for his plans for the Savoy Hotel, he also built about 12 private houses, including 25 Cadogan Gardens. His wide interest in social problems was reflected in other types of buildings and several projects for communal living.

Although some of his architecture shows Italian influence, its originality makes Mackmurdo a forerunner of the modern movement. He founded the Century Guild of artists (1882), based upon the teachings of William Morris (Morris, William), to produce better furniture and decorative accessories than were then available commercially. In the early 1880s he also designed textiles, tapestries, wallpaper, and metalwork often characterized by swirling plant forms, foreshadowing those of the later Art Nouveau. He began publishing The Hobby Horse in 1882, the first finely printed magazine on art. A friend of Morris, he was a founding member of the Society for the Protection of Ancient Buildings and was active in several organizations.