The Biblioteca Comunale degli Intronati is the public library located at Via della Sapienza [it] #3 of the comune of Siena, in Tuscany, Italy.

In 1786 the library received works housed in the Santa Maria della Scala (Siena), among them the precious Byzantine lectionary Gospels (designated by ℓ 283 on the list Gregory-Aland) already part of the treasure of the same institution (X. IV.

Atop the entrance to the Historical Reading room of the library is a plaque with the six statutes of the old Accademia in Latin: In the 1990s reconstruction led to designation of a specific hall.

Some material of the Museo archeologico nazionale was transferred to the former monastery adjacent to Santa Maria della Scala.

[4] In 1935 the collection of the library was estimated at 120,000 volumes, 86,000 brochures, 820 incunabula, 5,226 manuscripts, 20,000 autographs, and stamps.