St Dionis Backchurch was a parish church in the Langbourn ward of the City of London.

Of medieval origin, it was rebuilt after the Great Fire of London to the designs of Christopher Wren and demolished in 1878.

[1] The church was destroyed in the Great Fire of London in 1666, and rebuilt to the designs of Christopher Wren in 1674 at a cost of £5,737.

[4] The east end of the church, in Lime Street, had a pediment and two pairs of coupled Ionic pilasters with a large window below carved festoons.

It was designed by Renatus Harris and approved by a number of experts including George Frederick Handel.

[1] A City of London commemorative plaque noting the year of demolition is attached to the wall of the buildings that now occupy the former site of St Dionis Backchurch, opposite number 24 Lime Street EC3.

In 1878 the parish was merged with that of All Hallows Lombard Street under the Union of Benefices Act 1860 and the church demolished.