The medieval structure was lost in the Great Fire of London, and replaced by the present building, traditionally attributed to Sir Christopher Wren.

The church of St Michael, Cornhill is sited directly above the location of the western apse of the former London Roman basilica (built c. 90–120).

John Stow described the church as "fair and beautiful, but since the surrender of their lands to Edward VI, greatly blemished by the building of four tenements on the north side thereof, in the place of a green church-yard".

On the south side of the church was a churchyard with what Stow calls a "proper cloister", with lodgings for choristers, and a pulpit cross, at which sermons were preached.

[10] A folk tale, dating from the early 16th century, tells of a team of bellringers who once saw 'an ugly shapen sight' appear as they were ringing the bells during a storm.

The tower was eventually completed in 1722[3] with the aid of a grant from the Commission for Building Fifty New Churches, the upper stages being to the designs of its surveyor, Nicholas Hawksmoor.

[14] Scott demolished a house that had stood against the tower, replacing it with an elaborate porch, built in the "Franco-Italian Gothic" style (1858–1860), facing towards Cornhill.

[3][15] It is decorated with carving by John Birnie Philip, including a high-relief tympanum sculpture depicting "St Michael disputing with Satan".

New side windows were created in the chancel, and an elaborate stone reredos, incorporating the paintings of Moses and Aaron by Robert Streater[3] from its predecessor, was constructed in an Italian Gothic style.

[14] The pews also date from this time, and are an impressive complete set of victorian church furnishings, with elaborately carved finials at the bench ends, each with a different design.

They were described in The Building News in 1861 as being of "oak of beautiful colour and texture, effectively rendered by the veteran Rogers, who is one of the most successful imitators of the renowned Grinling Gibbons.

Williams built a three-bay cloister-like passage, with plaster vaults, on the south side of the building, and in the body of the church added richly painted decoration to Wren's columns and capitals.

In what the Building News described as a "startling novelty", a circular opening was cut in the vault of each aisle bay and filled with stained glass, and skylights installed above.

[19] A First World War memorial was unveiled beside the entrance to the church in 1920, featuring a bronze statue of St Michael by Richard Reginald Goulden.