Trevithick (/trəˈvɪθɪk/ trə-VITH-ik) is a Cornish surname. Notable people with the surname include:

• Francis Trevithick (1812–1877), one of the first locomotive engineers of the London and North Western Railway
• Jonathan Trevethick (1864–1939), New Zealand politician
• Paul Trevithick (born 1959), American inventor, engineer and entrepreneur
• Richard Trevithick (1771–1833), British inventor, mining engineer and builder of the first working railway steam locomotive
• William Edward Trevithick (1899–1958), Irish botanical illustrator