(ABT 1618-FEB 1698)
+---Thomas Trevithick (ABT 1664-MAR 1723)
| | +---Thomas Couch
| +---Peternell Couch 
(ABT 1640-DEC 1696)
| +---Elizabeth ?
+---Thomas Trevithick (ABT 1697-FEB 1771)
| | +---John Peters (ABT 1639-)
| +---Mary Peters (ABT 1665-)
| +---Marrian Spry (ABT 1643-)
+---Thomas Trevithick (ABT 1736-MAR 1804)
| | +---John Bennett (ABT 1680-JAN 1717)
| +---Mary Bennett (ABT 1706-1742)
| +---Pricilla ? (ABT 1680-)
+---John Trevithick (ABT 1778-DEC 1854)
| | +---John Sarel (ABT 1707-)
| +---Rebecca Searle (ABT 1733-MAY 1823)
| +---Jone Pasco (ABT 1711-)
+---Thomas Trevithick (ABT 1806-1887)
| | +---Richard Parrow (ABT 1752-MAY 1824)
| +---Honor Perrow (21 APR 1782-1857)
| +---Jane Sara ? (ABT 1749-JAN 1823)
+---John Trevithick (ABT 1834-07 SEP 1885)
| | +---Thomas Bassett (ABT 1779-)
| +---Susanna Bassett (ABT 1805-1891)
| +---Elizabeth Glanville (ABT 1783-)
+---William John Trevithick (07 OCT 1857-01 APR 1928)
| | +---William Kennedy (ABT 1805-)
| +---Ann Kennedy (ABT 1831-1903)
+---George Edward Trevithick (17 JAN 1894-05 FEB 1953)
| | +---George Tonkin
| | +---George Tonkin (1758-)
| | | +---Jane ?
| | +---James Prout Tonkin (ABT 1800-)
| | | +---Jennifer (Jane) Prout
| | +---William Tonkin (ABT 1831-)
| | | +---Jane Tredinnick
| +---Elizabeth (Bessie) Paull Tonkin (ABT 1862-1942)
| | +---Joseph Wills
| +---Eliza Wills (ABT 1828-)
| +---Martha ?
William John Trevithick (14 AUG 1920-17 FEB 1988)
| +---John Richards (1865-)
+---Dora E Richards (15 OCT 1891-1975)
+---Nellie ? (1869-)