Caffo was a sixth-century Christian in Anglesey, north Wales, who is venerated as a saint and martyr. The son of a king from northern Britain who took shelter in Anglesey, Caffo was a companion of St Cybi, and is mentioned as carrying a red-hot coal in his clothes to Cybi without his clothes getting burnt. After leaving Cybi, Caffo was killed by shepherds in the south of Anglesey, possibly acting in retaliation for insults Caffo's brother had paid to the local ruler. The area where he died has a village, Llangaffo, named after him, as well as the parish church of St Caffo, Llangaffo.

St Caffo's Church, Llangaffo is a 19th-century church, in the south of Anglesey, north Wales, about 5 miles (8.0 km) from the county town, Llangefni. It was constructed in 1846 to replace the previous medieval church in the village of Llangaffo. The new building includes a number of monuments from the old church, and has a spire which is a prominent local landmark. The churchyard has part of a stone cross dating from the 9th or 10th century, and some gravestones from the 9th to 11th centuries. It is dedicated to St Caffo, a 6th-century martyr who was killed in the vicinity.