Josiah Quincy VI (/ˈkwɪnzi/; October 15, 1859 – September 8, 1919) was an American politician from Massachusetts who served as mayor of Boston from 1896 to 1900. His grandfather Josiah Quincy IV (known as Josiah Quincy Jr.) and great-grandfather Josiah Quincy III also had served as mayors of Boston.

Quincy was born in Quincy, Massachusetts, on October 15, 1859, and pursued a career in law. A Democrat, he was a member of the Massachusetts House of Representatives from 1887 to 1888 and from 1890 to 1891.

Quincy was an unsuccessful candidate in the 2nd District of Massachusetts' congressional election in 1888 and served as the chairman of the Massachusetts Democratic Party from 1891 to 1894 and in 1905 to 1906. He was appointed as the United States Assistant Secretary of State by President Grover Cleveland in 1893 but resigned after six months. As Assistant Secretary of State, he filled all jobs under him with Bay Staters.^[4]

Quincy served two terms as mayor of Boston, being elected in December 1895, re-elected in December 1897, and holding office from January 1896 to January 1900.

He appointed a board of advisors, made up of Boston's leading businessmen, to guide him in the matters of taxes, business, and finance. In 1899, he united the city's various railroad terminals by building the South Station union station, which cost $3.6 million.^[5] It soon became the busiest station in New England.^[6] He saw to it that many playgrounds, public baths, and gymnasia were created during his mayoralty.^[7]

He was an unsuccessful candidate for governor of Massachusetts in 1901, and a delegate to the Massachusetts constitutional convention in 1917. Quincy was an unsuccessful candidate for Massachusetts attorney general in 1917. He was a member of the Massachusetts Society of Colonial Wars.

Quincy died on September 8, 1919^[6] at age 59.

• Timeline of Boston, 1890s