The church was designed by Joseph Hansom in a Gothic Revival style. Much of the original interior decoration was painted over in the 1970s, and the altar moved forward. The building is being gradually restored as part of the “Oxford Oratory – Reaffirmation & Renewal” campaign.

The church consists of a single nave and five side chapels. To the left of the sanctuary is the Sacred Heart chapel, and the Lady Chapel is to the right. There are also chapels dedicated to St Philip Neri (formerly St Joseph’s chapel) and Our Lady of Oxford (also known as the relic chapel).