The Oliveira Lima Library is a collection of books, manuscripts, pamphlets, maps, photographs and works of art that is dedicated to the history and culture of Portugal and Brazil. The original collection of 40,000 volumes was the personal library of the Brazilian diplomat, historian and journalist Manoel de Oliveira Lima (1867–1928).

The library holds 60,000 printed works—including books, serials, pamphlets, maps and broadsides—as well as more than 700 manuscripts. Among the strengths of the collection are Portuguese chronicles from the age of exploration; the history of the religious orders in the Portuguese world, especially works by and about Jesuits; the social, cultural and diplomatic history of 19th-century Portugal and Brazil; and the complete works of a wide range of Portuguese and Brazilian writers. The library also houses the Oliveira Lima Family Papers, comprising letters from more than 1,400 correspondents, including the leading Portuguese and Brazilian writers of Oliveira Lima’s day; 60 volumes of scrapbooks containing Oliveira Lima’s journalistic writings; and a distinguished collection of artworks, maps and 19th- and early 20th-century photographs. Although its focus is the Portuguese world, especially Brazil, the collection also includes materials for the study of Asia, Africa, India, and other parts of Latin America.

The Scholar's Guide to Washington, D.C.: Latin American and Caribbean Studies (Woodrow Wilson International Center, 1992) states that the library generally is considered the finest collection of Luso-Brazilian materials in the U.S. The Library of Congress duplicates and supplements some of the materials found in the Oliveira Lima Library, but there is no other specialized collection for comparable depth, particularly for the study of Portuguese expansion in the sixteenth century and for the social and cultural history of Brazil from the arrival of the Portuguese court (in 1808) to 1930.

Since 1920 the library has been an integral part of the Catholic University of America and has played a leading role in the development of Portuguese and Brazilian studies in the United States, Latin America and Europe. The library has elevated the university’s profile on a global scale. In recent years Brazil’s emergence as a regional and world power has stimulated increased demand for the study of Brazilian history and culture and of the Portuguese language, calling attention to the library’s strategic value as a foundation for new academic initiatives and partnerships. Visiting researchers and the library's staff have organized exhibitions of library materials and participated in lectures and conferences at the Catholic University of America and at many other universities, libraries, research institutes and museums.