The Cathedral Church of All Saints, Derby, better known as Derby Cathedral, is a cathedral church in the city of Derby, England. In 1927, it was promoted from parish church status to that of a cathedral, creating a seat for the Bishop of Derby, which new Episcopal see was created in that year. The original church of All Saints was founded in the mid-10th century as a royal collegiate church, dedicated to All Saints. The main body of the church as it stands today is a Georgian rebuilding by James Gibbs, completed in 1725. The tower dates from the 16th century, and a retroquire was added in the 20th century.

The original church, dedicated to All Saints, was probably built in about 943 by the Anglo-Saxon King Edmund I as a royal collegiate church, of which building no trace survives. Following the Norman Conquest of 1066, and according to the Domesday Book of 1086, it belonged to the king, and was served by a college of seven priests.

The Saxon building probably became structurally unstable, and was therefore demolished. A new building was constructed in the 14th century, which surviving drawings show was about the same size as the present building. In 1510–1532, the surviving 212-foot (65 m) tower was built in the Perpendicular Gothic style. On top of the tower are twelve large sculpted grotesque animal figures, three per face, and the sculpted stone head of a Green Man can be seen on each side of the main West Door at the base of the tower. The tower is built with Ashover Grit sandstone, sourced from nearby Duffield Bank quarry.

in 1556, during the persecutions of Protestants during the reign of Queen Mary (1553–1558), Joan Waste was tried for heresy within the Church of All Saints, and was executed on the Burton Road in Derby.

The fabric of the church appears to have deteriorated severely from about 1650, and was in a ruinous state in 1700. In February 1723 the vicar, Dr Michael Hutchinson, having decided that a new building was required, made the decision unilaterally to demolish the church, and employed a gang of workmen to accomplish the task overnight. Having accepted this fait accompli handed to them, the Mayor and Corporation of Derby commenced fundraising for the building of a new church by inviting subscriptions for the purpose, and made the first donation themselves. Dr Hutchinson expended much effort in fundraising, which exertion may have adversely affected his health. He made a significant personal financial contribution to the fund, and his efforts are recorded on a memorial tablet in the South Aisle. Having encountered numerous disputes, Hutchinson eventually resigned in 1728 and died about eighteen months later, leaving numerous outstanding debts.

With the original 1530s tower retained, the rest of the church was rebuilt to a Neo-Classical design made in 1725 by the architect James Gibbs. In his Book of Architecture, Gibbs wrote as follows regarding All Saints' Church: "It is the more beautiful for having no galleries, which, as well as pews, clog up and spoil the insides of churches ... the plainness of this building makes it less expensive, and renders it more suitable to the old steeple". To offset the rather austere interior, Gibbs introduced a wrought iron chancel screen, extending across the entire width of the church, manufactured by the local iron-smith and gate-maker Robert Bakewell, but not completed until five years after the new church was opened. The first sermon was preached in the new church on 25 November 1725.

By Order in Council on 1 July 1927, All Saints' Church became a cathedral. The new building was later extended eastwards with the addition of a retroquire designed by Sebastian Comper, constructed between 1967 and 1972.

The cathedral was registered as a charity on 9 April 2024, with the Registered Charity Number 1207768.