St Michael's Church is situated within a churchyard whose north-eastern boundary is curvilinear, with its north-east corner delineated by the A482. The churchyard appears to have been extended to the west. The church was not a parish church during the post-conquest period, but a chapelry of the Deanery of Sub-Aeron. At that time it was a posession of St Davids as a prebend of the collegiate church of St David's, Llanddewi Brefi (NPRN 96671). By 1833 Llanfihangel Ystrad had become a parish, with the living a discharged vicarage in the patronage of the Bishop of St Davids as an appropriation. The Vicarage is immediately south-east of the church, bounded by the churchyard (north-west) and A482 (north-east). There is a spring within the southern corner of The Vicarage curtilage, which continues along its south-eastern boundary.

The medieval church survived until 1877. The current square, scalloped font with cylindrical stem dates from the twelfth century. In 1810 the church reportedly consisted of nave and north aisle, seperated by an arcade of four two-centred arches. There was also, reportedly, a carved rood screen bearing the inscription 'MILET. CW. 1962. I.E. ME. FECIT.'. In 1847 there was no seperate chancel, no porch, and an open bellcote at the west end. The current bell was cast by William Evans, Chepstow in 1738.

The church was entirely rebuilt in 1877-1878, on the same site and in the same location as its predecessor but retaining nothing from the earlier fabric. It is a Grade II Listed Building, constructed of local rubble stone with yellow oolite dressings. The church consists of four-bayed nave, three-bayed chancel, vestry (north of chancel centre bay), four-bayed north aisle and south porch and bellcote. Before 1928 a temporary timber bellcote was situated in the churchyard. The porch and bellecote were added in 1928, to the designs of C.W. Mercer.

Sources include:
Cambria Archaeology, 2000, Ceredigion Churches, gazetteer, 48

N Vousden, RCAHMW, 29 July 2014