Liverpool Cathedral is a Church of England cathedral in the city of Liverpool, England. It is the seat of the bishop of Liverpool and is the mother church of the diocese of Liverpool. The church may be formally referred to as the Cathedral Church of Christ in Liverpool. It is the largest cathedral and religious building in Britain, and the eighth largest church in the world.

The cathedral is based on a design by Giles Gilbert Scott and was constructed between 1904 and 1978. It is the longest cathedral in the world; the total external length of the building, including the Lady Chapel (dedicated to the Blessed Virgin), is 621 feet (189 m), its internal length is 480 feet (150 m). In terms of overall volume, Liverpool Cathedral ranks as the fifth-largest cathedral in the world and contests with the incomplete Cathedral of St. John the Divine in New York City for the title of largest Anglican church building. With a height of 331 feet (101 m) it is also one of the world's tallest non-spired church buildings and the fourth-tallest structure in the city of Liverpool. The cathedral is recorded in the National Heritage List for England as a designated Grade I listed building.

The Anglican cathedral is one of two cathedrals in the city. The Roman Catholic Metropolitan Cathedral of Christ the King is situated approximately 0.5 miles (0.8 km) to the north. The cathedrals are linked by Hope Street, which takes its name from William Hope, a local merchant whose house stood on the site now occupied by the Philharmonic Hall, and was named long before either cathedral was built.

J. C. Ryle was installed as the first Bishop of Liverpool in 1880, but the new diocese had no cathedral, merely a "pro-cathedral", the parish church of St Peter in Church Street. St Peter's was unsatisfactory; it was too small for major church events, and moreover was, in the words of the Rector of Liverpool, "ugly & hideous". The Liverpool Cathedral Act 1885 (48 & 49 Vict. c. li) authorised the building of a cathedral on the site of the existing St John's Church, adjacent to St George's Hall. A competition was held for the design, and won by William Emerson. The site proved unsuitable for the erection of a building on the scale proposed, and the scheme was abandoned.

In 1900 Francis Chavasse succeeded Ryle as Bishop, and immediately revived the project to build a cathedral. There was some opposition from among members of Chavasse's diocesan clergy, who maintained that there was no need for an expensive new cathedral. The architectural historian John Thomas argues that this reflected "a measure of factional strife between Liverpool Anglicanism's very Evangelical or Low Church tradition, and other forces detectable within the religious complexion of the new diocese." Bishop Chavasse, though himself an Evangelical, regarded the building of a great church as "a visible witness to God in the midst of a great city". He pressed ahead, and appointed a committee under William Forwood to consider all possible sites. The St John's site being ruled out, Forwood's committee identified four locations: St Peter's and St Luke's, which were, like St John's, found to be too restricted; a triangular site at the junction of London Road and Monument Place; and St James's Mount. There was considerable debate about the competing merits of the two possible sites, and Forwood's committee was inclined to favour the London Road triangle. However, the cost of acquiring it was too great, and the St James's Mount site was recommended. An historian of the cathedral, Vere Cotton, wrote in 1964:

Looking back after an interval of sixty years, it is difficult to realise that any other decision was even possible. With the exception of Durham, no English cathedral is so well placed to be seen to advantage both from a distance and from its immediate vicinity. That such a site, convenient to yet withdrawn from the centre of the city … dominating the city and clearly visible from the river, should have been available is not the least of the many strokes of good fortune which have marked the history of the cathedral.

Fund-raising began, and new enabling legislation was passed by Parliament. The Liverpool Cathedral Act 1902 (2 Edw. 7. c. ccxxxi) authorised the purchase of the site and the building of a cathedral, with the proviso that as soon as any part of it opened for public worship, St Peter's Church should be demolished and its site sold to provide the endowment of the new cathedral's chapter. St Peter's place as Parish Church of Liverpool would be taken by the existing church of St Nicholas near the Pier Head. St Peter's Church closed in 1919, and was finally demolished in 1922.

In late 1901, two well-known architects were appointed as assessors for an open competition for architects wishing to be considered for the design of the cathedral. George Frederick Bodley was a leading exponent of the Gothic Revival style, and a former pupil and relative by marriage of Sir George Gilbert Scott. Richard Norman Shaw was an eclectic architect, having begun in the Gothic style, and later favouring what his biographer Andrew Saint calls "full-blooded classical or imperial architecture".