The baptistry in the south transept has the remains of the original groining which was badly damaged during the 1828 alterations.

The early medieval stone font which came from Gogar church was installed in 1955. The bowl is roughly hewn and originally would likely have been lined with metal. Gogar church lies a mile or so to the west of Corstorphine but is no longer used for public worship, its congregation having united with Corstorphine Old Parish many years ago.

The large south window is by Gordon Webster and replaced, in 1970, a nineteenth-century memorial window. The theme is Baptism and the Holy Spirit emanating from the enthroned Christ. Beneath this window is a recessed tomb bearing an effigy of an armored knight.

The figure is finely carved and although popularly believed to be that of Sir Adam Forrester who died in 1405, it could well be that of a succeeding member of that family, as the armour is of a design and fashion attributed by experts to a period some thirty years later.

The heraldic panels beneath the tomb appear to relate more to Sir John Forrester, his elder son, whose tomb is in the chancel. Adjacent to the tomb is a credence table and a recess which was previously the site of an altar into which a sculptured panel by Isobel Reid has been set and above which has been placed a tapestry by Dovecot Tapestries, Corstorphine, from a cartoon by Sax Shaw.

On the opposite wall is a six-ringed stone which at one time covered the burial vault of the Watsons of Saughton which lies beneath the floor in front of the transept. This memorial slab is dated 1620 and has a long ; Roman-lettered inscription from Ezekiel, Chapter 37 in the Authorised Version. The Watson family were influential landowners of Saughton House and estate in the parish of Corstorphine for approximately three centuries from 1537.