Hardwick is probably best known for London's demolished Euston Arch and its twin station, the original Birmingham Curzon Street, which stands today as the oldest railway terminus building in the world.

Philip Hardwick entered the Royal Academy Schools in 1808 and then studied in France and Italy from 1815 to 1819.

[3] At Babraham Hall in 1822–1823, on the site of a long-demolished sixteenth-century house, Hardwick adopted a Jacobean style, using red brick with limestone dressings.

[4] Brick was used again at Lincoln's Inn, when, in 1843–1845, Hardwick, in collaboration with his son, built a new hall and library.

In 1831 his father in law, the architect John Shaw Senior, helped elect Hardwick as a fellow of the Royal Society.

In 1839 he was one of the judges for the new Royal Exchange building in the City of London, and was appointed to select the design for the Oxford Museum in 1854.

Philip Hardwick's pupils included John Loughborough Pearson, Gothic revival architect of Truro Cathedral, Thomas Henry Wyatt (1807–1880), T. Roger Smith (1830–1903),[11] and Charles Locke Eastlake (1836–1906).

Like Inigo Jones some 200 years earlier, Hardwick had been inspired by Italian architecture, following a trip to Italy in 1818–1819.