The Old Library, designed by Tachu Naito, Kenji Imai and Kin-ichi Kiriyama, was completed in 1925. This 5-storey building, with a total area of 1,195 tubo (about 3,944 square meters), was used initially as the University Library. The reading room was housed in a separate 2-storey building, and had a seating capacity of 500. Being one of the prominent libraries established at the end of the Taisho period, it has remained a symbol of Waseda University to this day, along with the Okuma Auditorium and the Theatre Museum.

The Old Library and the administration building were extended in 1934 and 1955, respectively. However, the Old Library relinquished its role as the university’s main library after the New Central Library (located where the Abe Stadium used to be) was completed in 1990. It now serves to dispatch historical and cultural documents regarding Waseda University.,such as materials on the Okuma Memorial Room, the University History Material Center and, since 1998, the Yaichi Aizu Memorial Museum.

In the front hall, visitors are greeted by the masterpiece "Meian", which dates back to 1927. It was painted on the world's largest hand-made washi (Japanese paper) measuring 5 meters by 40 centimeters and weighing 11 kilograms (manufactured by Heisaburo Iwano, the founder of the Echizen paper works in Imadachi-cho, Fukui Prefecture,). The masterpiece was painted free of charge by Taikan Yokoyama and Kanzan Shimomura, two artists who represented the modern Japanese style of painting.

In April 1999, the Old Library was designated as one of the first of the "Tokyo Metropolitan Historic Buildings” along with the Okuma Auditorium.