Since the opening of the Church, there have been many changes to the interior of the church, many of which reflect the liturgical changes of Vatican II. A comprehensive renovation of the church was completed in March 2012. The mosaics and altars were cleaned and restored. The ceiling was painted with hand detailing. The round modern sanctuary was covered in marble tile and the faded floor tiles were replaced with replicas of the original patterned floor.
The interior of the church is adorned in mosaic most notably the work of Gabriel Loire of Chartres entitled, “The story of the Redemption in mosaics from the Old and New Testaments”. It is located along the central elevation of the nave and was completed in 1961.
The mosaic in the apse over the high altar is a mosaic of Christ the Most Holy Redeemer. Much of the imagery of the representation of Christ was inspired by the theme of the Kingship of Christ. It was designed and executed by the firm of Ludwig Oppenheimer of Manchester, and installed in 1936. There is a very definite Byzantine feel to this mosaic, which appears to preside over the worshipping congregation of Clonard assembled beneath. But the image is not triumphalist! The arms of this Redeemer King are open in welcome, waiting to embrace the people of God who come to pray.