The Church of Our Lady and St Michael in Abergavenny, Monmouthshire, is a Roman Catholic parish church. A Grade II* listed building, it was built between 1858 and 1860 to a design by Benjamin Bucknall.

Abergavenny remained a Catholic stronghold in the years after the Reformation, and its first Catholic church built after the Reformation was on Frogmore Street.^[1] This was replaced as the town's main Catholic church by Our Lady and St Michael's in 1860.^[1] The construction of the church was funded by a local solicitor, John Baker Gabb, and the architect was Benjamin Bucknall.^[2] Bucknall was engaged on the building of Woodchester Mansion, Gloucestershire, for another Catholic client, William Leigh, and, aged only 25, was seen as a coming man in Catholic architectural circles. Bucknall's intellectual and architectural influences were the work and ideas of Augustus Pugin – he converted to Catholicism in the year of Pugin's death – and the French Gothic Revival architect Eugène Viollet-le-Duc, with whom Bucknall was in regular correspondence.^[3]

The church is constructed in Decorated Gothic style, with an accompanying Tudor Gothic presbytery.^[2] Built of Old Red Sandstone, with Bath Stone dressings and slate roofs,^[1] the church comprises a nave, North and South aisles and a chancel.^[4] An intended "grand tower and spire" were never built.^[2]

Simon Jenkins describes the church as "a bold composition of church and presbytery."^[5] The interior of the church is largely unchanged since its construction with all its original Victorian furniture and furnishings intact.^[1] The presbytery is similarly unspoilt.^[1] The church also has "an exceptionally fine collection of medieval and later vestments".^[4]