Pethick is a surname. Notable people with the surname include:
Christopher J. Pethick (born 1942), English theoretical physicist Dorothy Pethick (1881–1970), British suffragette Emmeline Pethick-Lawrence (1867–1954), British suffragist Frederick Pethick-Lawrence, 1st Baron Pethick-Lawrence, PC (1871–1961), British Labour politician Robbie Pethick (born 1970), retired English football defender
See also Egloskerry, Cornwall - where a legal precedent was set by the local Pethick family