The church was designed, by J. Hansom, the architect of Arundel Cathedral, and the Holy Name church in Manchester. It is of French Gothic inspiration, and was originally colourfully decorated in an Italianate style. In 1954 the decoration was all painted over with two-tone grey. The last repainting in the 1970s gave the church the colours which can be seen today.

As you enter the church you find the Holy Water stoup before the middle column. This was given by the Paravicini family in memory of Fr Gerard Manley Hopkins SJ, who was curate at St Aloysius' for a year. We take water and sign ourselves with it in honour of the Holy Trinity to remind ourselves that we have been baptised.

Turning right, there is a statue of St Anthony, one of the most popular of all the saints, a Franciscan preacher of the thirteenth century. Today, offerings left for St Anthony are used to help the poor of our city.

Just beyond St Anthony, at the start of the side aisle, is the Baptistery, the Chapel of Our Lady of Oxford.