The parish engaged the master mason George Dowdeswell to start the work of rebuilding in 1668. The work was carried forward between 1671 and 1687 under the direction of Sir Christopher Wren, the body of the church being substantially complete by 1676. At a cost of £9,579 19s 10d St Magnus was one of Wren's most expensive churches. The church of St Margaret New Fish Street was not rebuilt after the fire and its parish was united to that of St Magnus.