St Mawes takes its name from one of the 170 Celtic saints who are commemorated through place names throughout Cornwall. It is thought that St Mawes, or St Mauditius (or Maudez) arrived in the middle of the 5th century AD and took up residence in what was probably an early fishing community, close to a well which now bears his name and can be found only a short walk down the hill from the church. The well had been rediscovered in 1938 and was re-consecrated by the Anglican Bishop of Truro.

Mass was first celebrated in this church in 1938 after a group of local Catholics had raised money to buy, extend and restore the building. Its spiritual journey, however, had started back in 1875 when it was built as a Bible Christian chapel, a contemporary popular alternative break away from traditional Cornish Methodism.

With the foundation stone laid and commemorated on 6th May 1875, the first service was held on Christmas Day of the same year. The only other recorded fact of the early history is that this was the first church ever to have a woman minister, appointed in 1900. By 1932 the Bible Christians had reunited with the Methodists and the congregation moved to the Methodist Chapel in St Mawes. Five years later, the small Catholic community in the village raised the sum of £750 to buy the empty building and to have it restored and extended.

A presbytery was built just after the war but between 1938 and 1945, priests from Falmouth came to say Mass. With the new accommodation, priests would come and stay for short periods until 1956 when the first resident priest was installed, Mgr. Harold Shepherd CBE who had just retired as the Chief RC Chaplain to the Royal Navy. Mgr. Shepherd retired from the clergy in 1970 and was followed by Canon Adrian Chapple.

1970 also saw the start of renovation works as the building neared its 100th birthday. This was celebrated to the day on 6 May 1975 when a special ecumenical service was held. Restoration work was completed in 1978 and in 1979, the first confirmation was held for 30 years when 16 candidates – 8 children and 8 adult converts – received the sacrament.

The Golden Jubilee was celebrated by Canon Chapple in 1984.