The baptistery was originally intended to be in the area now designated as a Lady Chapel. It is unfortunate that the baptistery was never in fact located in this area but was moved to the right of the sanctuary area. The circular area of the original baptistery refers to early Christian centrally planned baptisteries and martyria and the oculus in the roof of the baptistery links it to even earlier Roman structures.

The present baptistery however, does have a beautiful baptismal font carved in granite and covered with a hammered bronze lid. The aumbry, also in bronze, was designed by Chris Ryan, and holds the Holy Oils. On the wall of the baptistery there is a relief in bronze of the baptism of Christ by John the Baptist in the Jordan. It depicts Jesus standing in the water with John pouring water from a shell on his head. The shell was an ancient Christian symbol. The Holy Spirit in the form of a dove is seen descending on Jesus. The whole scene recalls the Baptism of Jesus as described by Mark 1:9-11.

There is a very close connection between the baptistery and the ambo from which the Word of God is proclaimed.