Josiah Quincy may refer to:Josiah Quincy I (1710–1784), American merchant, planter, soldier, and politician
Josiah Quincy II (1744–1775), American lawyer and patriot
Josiah Quincy III (1772–1864), American educator and political figure, mayor of Boston, 1823–1828
Josiah Quincy Jr. (1802–1882), American politician, mayor of Boston, 1845–1849
Josiah Quincy (1859–1919), American politician from Massachusetts, mayor of Boston, 1896–1900
Josiah Quincy (1793–1875), American politician and lawyer in New Hampshire