Chelliana Library, Public library in Palazzo Mensini, Grosseto, Italy.

The Chelliana Library occupies the 1898 Palazzo Mensini on Via Mazzini, in Grosseto's historic centre, in rooms that previously housed the former seminary and the Royal Gymnasium and Lyceum. It is the main public library of the city and the reference institution for the province, with a documentary heritage of about 130,000 items.

Canon Giovanni Chelli opened the library on 1 March 1860 in three rooms of the vacant Episcopal Palace, with about 9,000 volumes from bequests by Bishop Giovanni Domenico Mensini and Vicar Domenico Pizzetti. Chelli donated it to the municipality in 1864; it was inaugurated as the Biblioteca comunale Chelliana on 30 March 1865. By May 1866 it held some 50,000 volumes in five Brunet sections. After Bishop Anselmo Fauli's 1867 appointment, the library was evicted from the diocesan residence.

The library is named after Canon Giovanni Chelli, who founded it in 1860 and donated it to the municipality in 1864; the ceremonial inauguration under his name took place on 30 March 1865. Writer Luciano Bianciardi directed it from 1951 to 1954, a period tied to his later novel about the city.

The library operates with different schedules depending on the season and day of the week, with shorter hours on Saturdays. It is helpful to check current opening hours before visiting, especially if planning to go on weekends.

The library's name honours Canon Giovanni Chelli, who founded it in 1860 and died in October 1869, before seeing it settled in a permanent home. Its collection peaked at about 70,000 volumes by 1934, when Angelo Davoli counted thirty-two incunabula and several hundred manuscripts.