Penberthy is a locational surname of Cornish origin, which meant a person from Penberthy Cross in Cornwall. Notable people with the surname include:Bob Penberthy, British rugby player
Beverly Penberthy, American actress
Bryan Penberthy, American poet
David Penberthy, Australian journalist
James Penberthy (1917–1999), Australian musician
Joanna Penberthy, Welsh Anglican bishop
Larry Penberthy (1916–2001), American businessman
Mike Penberthy, American basketball player
Stan Penberthy (1906–1989), Australian football player
Tony Penberthy, British cricket player