St. Leonard's, Shoreditch was a church in Shoreditch. It was located near the Curtain, being known as the "actor's church". Barbara Wright pointed it out shortly after the TARDIS arrived in 1601 Shoreditch. (AUDIO: The Hollow Crown)
Behind the scenes
In the real world, Shoreditch Church and St. Leonard's Shoreditch are one and the same, however no DWU fiction has connected the two.