The Library as been an integral part of the former Pius XII College since its inception. It was established in 1954 as the nucleus collection of the former Pius XII College. The current building site of the Library was constructed in 1954. The Library played a central role during the UBBS, UBLS historical eras and as the university metamorphosed over the years.

Today the library still forms an integral part of academic environment at the National University of Lesotho (NUL).

The current building where the library is situated was constructed in 1964. The building was named after Thomas Mofolo when it became the NUL Library. The Library has since evolved into a conglomerate of a conventional library, the archives, documentation unit, a museum section. It offers other services that harmoniously provide information for academic and related purposes.

The library service operates from the Roma campus-based Thomas Mofolo Library (TML) building that is the hub and the source of a variety of information resources. 

The NUL management saw the need to extend the original Library building to cope with the current and increasing student population and the NUL community in general. The new library extension at the Roma campus has been constructed and furnished.

The new extended block is currently being utilized by both student and NUL staff library users as well as external users.

Thomas Mofolo Library (TML) has over the years, extended its services through to other NUL campus designated areas and the Institute of Extra Mural Studies (IEMS).