Palazzo dell'Ambrosiana, Italian Baroque palace in central Milan, Italy.

Palazzo dell'Ambrosiana is a Baroque building in central Milan that fills an entire city block with two separate entrances on Piazza Pio XI and Piazza San Sepolcro. Inside are a historic library, art gallery, and spaces for artistic learning connected by corridors and courtyards.

A cardinal commissioned the palace's construction in 1609, with several architects contributing to its design. The project developed into an institution dedicated to preserving books and artwork for the city.

The library within the palace was among the first of its kind, bringing together books, art, and artistic training in one place. Visitors can see how this institution has preserved and shared knowledge and creative learning across centuries.

The palace has two entrances: the historic one on Piazza San Sepolcro, framed by a classical pronaos with four Doric pilasters and the Borromeo coat of arms, and the 19th-century one on Piazza Pio XI, set between two Ionic columns. The first stone laid by Federico Borromeo on 30 August 1609 is kept at the entrance. The library occupies the ground floor, the Pinacoteca the upper rooms.

The first stone, laid by Cardinal Federico Borromeo on 30 August 1609, is kept at the palace entrance. The library he opened the same year was among the first public libraries in the world. Its holdings include Leonardo da Vinci's Atlantic Codex and letters of Lucrezia Borgia displayed with a lock of her hair.