Saint Ia of Cornwall (also known as Hia, Hya, Eia or Ives) was a 5th or 6th century Cornish evangelist and martyr.
Ia was said to have been an Irish princess, the sister to Saint Erc. She was a spiritual student of Saint Baricus and travelled as a missionary to Cornwall where she joined Saints Fingar and Piala. Legend holds that they had up to 777 companions and that she sailed across the Irish Sea on an ivy leaf. Ia was martyred on the River Hayle and buried at St Ives, Cornwall, where St. Ia's Church, St. Ives, of which she is now the patron, was erected over her grave. The town built up around it. Her feast day is 3 February. She is mentioned in the Life of St Gwinear and John Leland gives details from a Latin life of Ia which is no longer extant. The church of Plouyé in Brittany was probably dedicated originally to this saint.
↑Doble, G. H. (1960) The Saints of Cornwall: part 1. Truro: Dean and Chapter; pp. 89-94