Sir John Arundell (circa 1366 – 11 January 1435), called The Magnificent, of Lanherne in the parish of St Mawgan in Pydar in Cornwall, was an English knight who inherited large estates in the County of Cornwall.

In his will dated 1433, he bequeathed money for the preservation of the head of St Piran in the chapel at Perranzabuloe.

[2] He served in the navy 1418–19; married Annora Lambourn of Perranzabuloe, which brought to the Arundells several more Cornish manors.

Arundell made financial arrangements in his will that would maintain a chantry of five chaplains and a clerk at St Columb Major.

He also left money to build a chapel in the parish church of St Columb Major to house his own tomb.