Trethewey is a surname of Cornish origin. It is derived from any of the various settlements in Cornwall called Trethewey.[1][2]

Notable people with the surname include:

  1. ^ Hanks, Patrick; Hodges, Flavia; et al. (2002). The Oxford Names Companion. Oxford University Press. p. 621. ISBN 0198605617
  2. ^ "Cornish Surnames - extensive A-Z list". Ancestry.com. Archived from the original on 2011-07-07. Retrieved 2011-06-18.