Samuel Swett Green was born in Worcester, Massachusetts on February 20, 1837. He graduated from Harvard University in 1858 and from Harvard's Divinity School in 1864. He did not pursue a career in the ministry however, but worked in a bank for several years before accepting the position of librarian at the Worcester Free Public Library on January 15, 1871. His uncle, Dr. John Green, had founded the library in 1859. When Samuel Swett Green took charge, the library had been sorely neglected, but it flourished under his care. One of his most influential acts, which began on December 8, 1872, was to open the library on Sundays. His library was one of the first in New England to open on Sunday, and the example he set was soon followed by the Boston Public Library. Although he was not the founder of interlibrary loans, he was certainly a proponent of the service. Furthermore, his work to establish strong relationships between libraries and schools was one of his greatest contributions to the field, and his book Libraries and Schools was published in 1883.
Green was also one of the founders of the American Library Association and his name appears on the ALA charter. He was very active in the ALA serving as its vice-president from 1887-1889 and 1892-1893, and as its president in 1891. Green was appointed by the governor of Massachusetts in 1890 as an original member of the Free Public Library Commission, and he served on the commission until 1909. In 1893, he presided over the World's Congress of Librarians in Chicago. He retired from all public activities in 1909 and devoted the remainder of his life to writing. He died on December 8, 1918.