The church is sited on Old Street, north of the City of London. It was built to relieve the City church of St Giles-without-Cripplegate, Cripplegate, under the Commission for Building Fifty New Churches, an attempt to meet the religious needs of London's burgeoning 18th-century population. The ancient parish of St Giles lay partly within the City and partly outside its boundaries in Middlesex: under the Commissioners' scheme these two parts were to be separated, with the Middlesex portion (historically the Manor of Finsbury, becoming a new parish of St Luke's. Construction began in 1727 and was completed in 1733, when the church was consecrated on 18 October (St Luke's day), and the parish detached from that of St Giles.