The "west" (actually south) front and nave are copied on a reduced scale from Howden Minster in the East Riding of Yorkshire; the choir and sanctuary are closely modelled on those of Selby Abbey in North Yorkshire; the decorations of the groined vault are copied from the church of St Jacques in Liège, Belgium; the tower and spire, the latter the tallest in Lancashire at the time of building, are derived from the church of St Mary Magdalene, Newark-on-Trent in Nottinghamshire.

Two local businessmen, Daniel Lee (d. 1858) and John Leeming (d. 1877), each donated £1,000 towards the cost of the church and furnishings; both benefactors are commemorated in chantries at the liturgical east end of the choir.

Canon Beesley, then the administrator, succeeded in raising funds for repairs to the spire and generally refurbishing the fabric of the building.

He also oversaw the furnishing of the new chapel of the blessed sacrament in the "south" transept in 1884, to designs of Peter Paul Pugin, third son of A.W.N.

They were taken down and rebuilt by the Sheffield firm of O'Neill & Son under the direction of Charles M. Hadfield, grandson of the cathedral's original architect.

A further re-ordering of the choir (chancel) took place in 1988, including the removal of the original stone high altar and reredos, installed in 1853–55 to designs by George Goldie.

Its title is When I am lifted up I shall draw all to myself, and it depicts, in somewhat abstract form, the crucified Christ flanked by the Virgin Mary and the cathedral's patron, St. John.

While digital organs are still uncommon in cathedrals, the current instrument has a versatile stop list and is an improvement on its predecessor, with speakers located in the clerestory windows above the nave to help with choir and congregational singing.