Early Life
John Whichcote was the son of
John Whichcote of
Whichcote (in Shropshire) and his wife
Elizabeth Tyrwhit. By extrapolation down from younger generations, it's likely John was born in the 1470s.
Career
The Baronetage of England1 has this John being a JP and high sheriff of Lincolnshire, but I think this is a confusion with his father, because the John Whichcote who was High Sheriff of Lincolnshire held this office in 1466, when this John Whichcote (subject of this page) was either unborn, or still a child.
Footnotes
[1] The Baronetage of England, Rev. William Betham, Volume 2, Ipswich (1802), pages 40-43