The Church of St Tysoi, is the parish church of Llansoy, Monmouthshire, Wales and sits to the south of the village. It is in the Perpendicular style and is a Grade I listed building as of 19 August 1955.

The church is medieval in origin, of Old Red Sandstone. The tower may be "no earlier than the early nineteenth century."* The church was lightly restored in the nineteenth century including work by John Pollard Seddon.

The interior has a fifteenth-century barrel roof and contemporary fittings. It also has some notable stained glass windows of the nineteen twenties and of the later twentieth century, including a "brilliantly coloured" "Genesis" window by Geoffrey Robinson.

• Newman, John (2000). Gwent/Monmouthshire. Buildings of Wales. London: Yale University Press. ISBN 978-0-300-09630-9.

• Artworks at St Tysoi, Llansoy