1650–1676) was an early English Quaker, often imprisoned for his beliefs, and a prolific writer of controversial tracts.
He was concerned in the schism of John Perrot about wearing the hat during prayer.
The Vision of John Perrot, 1682, contains on the back of the title page some in memoriam verses by Mason, dated 27 October 1676.
He seems to have taken a broad-minded view of the Perrot controversy, and wrote What matter whether hat be on or off, so long as heart be right?
A volume of manuscripts, formerly in the possession of a descendant, contained verses and letters addressed to judges and deputy-lieutenants of the county of Lincoln, besides correspondence with Albertus Otto Faber, a German doctor who cured him (see Faber's De Auro Potabili Medicinale, 1677, p. 6).