The Research Library collects materials to support scholarship in Byzantine, Garden and Landscape, and Pre-Columbian studies. In addition to supporting the research of staff and fellows, the library also admits researchers who come to Dumbarton Oaks on shorter visits. In addition to books and journals, the collection comprises microfiches and microfilms, maps, and an offprint file.
The holdings comprise more than ten thousand rare and unique materials, such as volumes, prints, drawings, photographs, musical scores, letters, and blueprints. Many volumes are available as digital facsimiles, and selections from the autograph letter collection are online with transcription, translation, and commentary. The Rare Book Collection also contains the Garden Archives, which makes over six thousand individual pieces of correspondence, drawings, and photographs publicly available.
With more than a million unique and historical items, archival collections in ICFA are divided into document, photograph, digital image, and moving image categories. Collections are generally comprised of administrative records, fieldwork papers, photographic prints, negatives, slides, oversize drawings, and moving images.