This surname is derived from a geographical locality. 'of Prideaux.' 'The ancient family of Prideaux trace their descent from Paganus, lord of Prideaux Castle, in Luxilion, Cornwall, in the time of William I': Shirley's Noble and Gentle Men (quoted by Lower). There is no doubt Prideaux gave name to the family of Prideaux. They are early found in the neighbouring county of Devon.

Roger de Prydeaus, or Prydyaus, or Prudeaus, Devon, 1273. Hundred Rolls.

Thomas de Prideas, Cornwall, 20 Edward I: Placita de Quo Warranto, temp. Edward I-III.

Geoffrey de Pridias, Devon, Henry III-Edward I: Testa de Nevill, sive Liber Feodorum, temp. Henry III-Edward I.

The castle of Prideaux, according to Tonkin (D. Gilbert's Cornwall, iii., 56), was "the seat of, and gave name to, a family which hath been very eminent both in this county and in Devonshire, and still flourisheth in both." "Some would derive it," he says, "from a French original: pres d'eaux, near the waters, for the sea formerly flowed up as high as this place." "The ancient family of Prideaux trace their descent from Paganus, lord of Prideaux Castle, in Luxilion, co. Cornwall, in the time of William I., where the family continued till the latter part of the fourteenth century." Shirley's Noble and Gentle Men.

(French.) From Presd'eaux, near the water.

PRIDEAUX: This ancient family are said to trace their descent from Paganus, lord of Prideaux Castle in Luxilion; from French prês d'eaux, near the waters, "the sea formerly flowing up as high as this place." I hare elsewhere derived this name from pratellum, diminutive of pratum, a meadow; but Tonkin thinks it may also be from pri, prid, clay, and aus, the same with als, the cliff or sea-shore. compare my notice of the name in Notes and Queries; Shirley's Noble and Gentle Men; and Lower's Patronymica Britannica.