Augustus Welby Northmore Pugin (March 1, 1812 - September 14, 1852) was an English-born architect, designer and theorist of design now best remembered for his work on churches and on the Houses of Parliament. He was the son of a French draughtsman, Augustus Charles Pugin, who trained him to draw Gothic buildings for use as illustrations in his books. This was the key to his work as a leader of the Gothic revival movement in architecture. Pugin became an advocate of Gothic architecture, which he believed to be the true Christian form of architecture. He attacked the influence of 'pagan' Classical architecture in his book "Contrasts", in which he set up Medieval society as an ideal, in contrast to modern secular culture.

After the burning of the Houses of Parliament in 1834, Pugin was employed by Sir Charles Barry to work on the new Parliament buildings in London. He converted to Roman Catholicism, but also designed and refurbished Anglican churches throughout the country. His views, as expressed in works such as True Principles of Christian Architecture (1841) were highly influential.

Other works include the interior of St Chad's Cathedral and New Oscott College, both in Birmingham.

Pugin produced a "mediæval court" at the Great Exhibition of 1851, but died suddenly after a mental collapse.