As part of the Anglo-Saxon church, there was a side-chapel at the east end of what is now the south aisle, matching the side-chapel in the east. No trace of the original is now visible above ground.
A very narrow south aisle, about 4' 6" wide, was built during Anglo-Saxon or Norman times. It was widened to its present alignment during the 13th century. In the west wall is an Early English lancet window which was later blocked and only opened out again in 1914.
In the 14th century a new chapel, much larger than the original Anglo-Saxon chapel, was built at the east of the south aisle, enclosing the original. The elaborate flat-headed south window has been heavily restored, but is of a 14th century design known elsewhere in Derbyshire. Most of the windows of the south aisle date from this time.
In 1842, a side gallery were built over the aisle. It was removed again in 1885 as part of the general restoration of the church. At the same time, the wall was rebuilt where it bulged badly, and a doorway now in the south chapel was moved there from the south aisle. Traces of the original can be found at the east end of the aisle, by the window dedicated to the Rev'd John Hare and his wife, Sarah.
In 1913 the blocked 13th century lancet windows in the west wall of the aisle was opened out.
In 1950 the pipe organ was removed from the south transept. The area was repaved with York stone and furnished as the Fynderne Chapel with a stone altar of Hornton stone and oak altar rails. The south-west stairway from the crypt was opened out and considerably repaired.
In 1998, the organ was again replaced and relocated to the Fynderne Chapel, standing against the east wall of the south transept.
The storage area at the south-west corner was created in 2010 as part of the Heritage Development of 2008 - 2010.