John Jones of Gellilyfdy

John Jones of Gellilyfdy (c. 1578 - c. 1658) was a Welsh lawyer, antiquary, calligrapher, manuscript collector and scribe. He is particularly significant for his copying of many historic Welsh language manuscripts which would otherwise have been lost.

Jones often styled himself as Siôn ap Wiliam ap Siôn, using the Welsh patronymic system, in his manuscripts.