The public library is housed in a mansion with historical, cultural and architectural value. The old building has the head office of the library system, located on the ground floor, and the offices of the Macao ISBN Agency, located on the second floor.
Sir Robert Ho Tung Library was constructed before 1894 and was originally the residence of Dona Carolina Cunha. Hong Kong businessman Sir Robert Ho Tung purchased it in 1918, using it as his retreat. He passed away in 1955 and in accordance with his will, the building was presented to the Macao Government for conversion into a public library.
Sir Robert Ho Tung Library was officially opened in 1958 to the general public. In 2005, a new building was constructed near the back garden of the mansion, making the library the biggest public library in Macau.