John Nichols Tom (or Thom) was born the son of innkeepers in 1799 at St Columb Major, Cornwall. He was baptised in the parish church on 10 November 1799. His parents were William and Charity Tom who kept the Joiners' Arms. Tom went to school in Penryn, attending Bellevue Academy (a "Classical and Commercial Academy"). At the age of about fourteen he transferred to the private school in Launceston that was run by Reverend Richard Cope, pastor of the local Congregational Church.