The William Allan Neilson Library, named after Smith's third president, serves as the social sciences and humanities library and includes the library administration offices.

The library also houses The Mortimer Rare Book Room, formed by removing fifteenth- and sixteenth-century books from the Neilson stacks in the early 1940s. Thanks to the generosity of alumnae and friends, the collection has grown to nearly 25,000 volumes and has expanded beyond its original role as protector of early printed artifacts.

The Alumnae Gymnasium, connected to Neilson Library, houses The Sophia Smith Collection, the oldest national repository for primary sources in women's history, the College Archives, which documents the history of Smith. Media Services, formerly known as the Nonprint Resources Center, is also housed in Alumnae Gymnasium. The media collections (videocassettes, DVDs, laserdiscs, audiotapes) have moved to Neilson Library and are available on request at the Circulation Desk. Classroom Support provides presentation services for classroom and special events. The Center for Media Production provides video, audio and photo production services; and equipment rental.