Arnold Dunbar Smith FRIBA (2 December 1866 – 7 December 1933)[1] was an English architect who in 1897 formed Smith & Brewer (1897 – 1949) with Cecil Claude Brewer (1871 – 1918) who were responsible for the design of the Mary Ward House in London (1899) and the National Museum and Gallery in Cardiff (1912) who are both Grade I listed buildings.

[2] The Passmore Edwards Settlement building established the partnership's reputation as arts and crafts architects working in the "Free Style" of the 1890s.

"[4] The partnership worked with the Welsh sculptor Sir William Goscombe John (1860–1952) to design the sculptures that would decorate the building.

[4] They became pioneers of the Neo-Classical Revival with this building, and it played an important role in establishing the American Beaux-Arts style of classicism in the United Kingdom.

After Cecil Brewer's death in 1918, Smith continued the work and he designed many residential houses as well as additions to the Fitzwilliam Museum (1924–1933).