The former churchyard of St Michael and All Angels Church is depicted on historic (1889, 1905, 1932) Ordnance Survey mapping. It is bounded by King Street (north), Laura Place (east), Great Darkgate Street, Michael's Place and Theatr Y Castell (south) and the current children's play area and castle grounds (west).

The first St Michael's Church, dedicated in 1787, was reportedly situated between the current church and the Parish Hall. The boudaries of the churchyard in relationship to the church building are given as 38ft from the east boundary; 52ft from the west boundary; 108ft from the north boundary; 80ft from the south boundary. The second St Michael's Church (NPRN 96222), the vestry of which has been preserved as part of landscaping works, was situated in the churchyard's north-west section. The current church, St Michael and All Angels (NPRN 110278), is situated in the churchyard's north-east section, adjacent to the site of the second church. The churchyard was extended (probably to the south, to include the area bounded by St Michael's Place and the current Theatr Y Castell) in 1903.

In 1973 the churchyard was controversially landscaped by Aberystwyth Borough Council. This involved the removal of headstones, the majority of which were arranged side-by-side (mounted in concrete) along the incline of the churchyard's western boundary banks. The area around the church, and the churchyard's entire north-western section were converted to a carpark.

In 1990 a burial vault was discovered by contractors cutting a new line for pipes, close to the north side of the present church. This was visited by Royal Commission staff, who noted that the vault was approximately 8ft deep and 10ft square. Three or four coffins, one thought to be of lead or iron, were clearly visible, set on lines of bricks. The pipe line was moved a few feet in order not to disturb the vault any further.

Sources include:
Ordnance Survey, 1889, first edition, 25in
Ordnance survey, 1906, second edition, 25in
Ordnance Survey, 1932, third edition, 25in
Ordnance Survey, modern, 1:10,000

N Vousden, RCAHMW, 24 July 2014