The Biblioteca was built in the Neo-classical style to the design of architect Stefano Ittar and was completed under the supervision of local architect Antonio Cachia. The Biblioteca adjoins the Grand Master's Palace and faces onto Misraħ ir-Repubblika. The façade is symmetrical and consists of two superimposed classical orders with the Doric order characterising the ground floor and the Ionic order featuring in the piano nobile. In front of the entrance is a loggia having exceptionally sculpted vaults. Above the central doorway is a balustrated balcony supported on a pair of double Doric columns, with pairs of Ionic columns within the balcony above which is a triangular pediment at parapet level.

The loggia supports the front part of the main reading hall at the piano nobile level. A grand entrance vestibule leads to a spacious flight of stairs that leads to the main library hall having a high ceiling. The interior of the library is lavishly furnished with period book cabinets from floor to ceiling and a large sculpture of the British Royal cipher graces the far end of the main hall.

Mepa scheduled the Biblioteca as a Grade 1 national monument as per Government Notice No. 276/08 in the Government Gazette dated March 28.