Newcomer is a surname. Notable people with the surname include:
Carrie Newcomer, American singer and songwriter
John Darlington Newcomer (1867–1931), American architect
Christian Newcomer (1749–1830), American farmer and preacher
Francis K. Newcomer (1889–1967), Governor of the Panama Canal Zone
Scott Newcomer, American politician
John Newcomer, American game developer, creator of Joust