Consists jointly of the files of the Modern Greek Studies Association (MGSA), established in 1968, and its official publication, the Journal of Modern Greek Studies , which began in 1983.

Consists of photographer Margaretta K. Mitchell's working files on the life and work of Ruth Bernhard (1905-2006), a German-born American photographer known for her black-and-white still lifes and female nudes. The working files contain research materials, drafts, and recordings and transcripts of interviews for Mitchell's biography of Bernhard, Ruth Bernhard: Between Art and Life (2000); drafts of Mitchell's essays that appeared in Ruth Bernhard's book The Eternal Body (1986); as well as correspondence, proofs, financial documents, and publicity materials related to both projects.

Consists of notebooks, manuscripts, correspondence, photographs, and ephemera documenting the working career of the poet and small-press publisher, Stuart Mills (1940-2006).

Consists of select correspondence, dating from 1946 to 2011, of art historian Charles W. Millard (1932-2017) with artists such as Sir Anthony Caro, Helen Frankenthaler, Carl Chiarenza, Mark Hewitt, Nick George, Jules Olitski, and others.

Consists of an open collection of manuscript material related to print collections of Leonard L. Milberg (Princeton Class of 1953): Leonard L. Milberg Collection of American Poetry, Leonard L. Milberg Irish Theater Collection, and the Leonard L. Milberg Collection of Jewish-American Writers.

Helmut Meyer was a German-born American citizen who fought for the United States in World War II and founded the Helmut Meyer Literary Agency in New York City. The collection contains files from the Helmut Meyer Literary Agency, propaganda from both the Allies and the Axis from World War II, manuscripts of Meyer's own work, and correspondence from friends and clients.

Consists of Merchant's manuscript drafts, correspondence, photographs, inscribed books, and other materials relating to the Greek poet Helenē Vakalo (1921-2001), and his English translation of Genealogia. The collection also contains writings by Giannēs Ritsos, Kimon Friar, and materials of other authors and publishers.

Consists of librarian Charles Haynes McMullen's data cards (numbering about 10,000) that McMullen compiled for his publication American Libraries before 1876 (2000).

The collection consists of the editorial files and personal papers of Margaret K. McElderry. Publisher files include editorial correspondence, legal documents, and production files related to specific authors and publications.

Consists of writings, diaries, correspondence, organizational records, clippings, and other personal papers of Irish poet Thomas McCarthy, including drafts of poetry, fiction, and nonfiction works from the 1970s through the 2010s; extensive diaries and notebooks on personal and literary topics; files related to his work with Cork 2005, the Triskel Arts Centre, and other cultural and arts organizations in Ireland; transcriptions and recordings of interviews and events; and teaching materials.

The McCarter Theatre was conceived as a permanent home for the Princeton University Triangle Club. McCarter began as a booking theater but ultimately moved into producing its own performances. The McCarter Theatre records document the history of the McCarter Theatre, including administration, performances and productions, and the building itself.

Mina Mauerstein-Bail is a development professional with extensive international experience in the links between health and economic development. These Papers include reports, study papers and background materials collected over the course of her career and reflecting her areas of expertise: HIV and development, water and sanitation, and supporting local government and community capacity to address HIV/AIDS issues.

H. Freeman Matthews, Jr., son of H. Freeman Matthews, was a career Foreign Service officer, serving with the State Department from 1952 to 1991. The collection consists of materials documenting Matthews, Jr.'s service with the State Department, in particular, his time as Deputy Chief of Mission in Cairo from 1976 to 1980.

Dean Mathey (d. 1972), Class of 1912, was a member of the Board of Trustees and an ardent supporter of the University. The collection documents Mathey's familial relationships, service to Princeton, tennis career and other activities from his undergraduate days to the end of his life.

Robert Massie (1956- ) has led a varied life as an Episcopalian priest, university lecturer, social and environmental activist, historian, and executive. His work has focused on advocating higher standards of corporate responsibility and social justice in the conduct of capitalism. Massie's papers document his research on South Africa and anti-apartheid movements and include reports, articles, interview notes, and surveys.

John R. Martin was a professor of Art History at Princeton University for 40 years, joining the faculty as a Woodrow Wilson Fellow in 1947. Consists of Martin's correspondence and his handwritten lecture notes from courses taught as well as his lecture appointments at other institutions.

Consists of scrapbooks of tearsheets and clippings, original artwork in pencil and in pen and ink, correspondence, financial documents, periodicals, permission agreements, and contracts spanning Henry Martin's career as a cartoonist and illustrator.

Anne Martindell was one of the first three women to serve in the New Jersey State Senate. After her four-year term ended in 1977, she served as director of the Office for Foreign Disaster Assistance, and was ambassador to New Zealand and Western Samoa for a two-year term. The papers document her career in politics and civil service, and also contain her unpublished memoirs and personal papers.

Consists primarily of correspondence with authors such as Gordon Lish, James Purdy, Cynthia Ozick, and Paul Bowles, among many others, along with some writings and publisher files of American literary critic and professor of literature Irving Malin (1934-2014).

Consists of photographs taken by American photographer Owen Luck, which are arranged according to three separate series: Wounded Knee 1973, Menominee 1975, and Pine Ridge Reservation life 2000-2001.

Consists of papers of Chinese journalist and political dissident Liu Binyan, including manuscripts, notes, drafts of speeches, reviews, correspondence, audiocassettes of interviews, and other material.

Consists primarily of letters written to Nathalie Waag by Enrique Lihn, a Chilean poet.

The George Lianis Papers consists of papers by and relating to the Greek academic and politician George Lianis (1926-2008). Included are autograph and typed manuscripts, as well as correspondence (personal and professional), loose photographs, one photograph album, slides, and printed material.

Samuel W. Lewis (1930-2014) was an American diplomat who is best known for his 1977-1985 service as U.S. Ambassador to Israel and active presence during the 1978 Camp David Summit. The Samuel W. Lewis Papers consist of speeches, correspondence, journals, oral history transcripts, and scrapbooks documenting Lewis's long career in the U.S. foreign service.

David Kellogg Lewis (1941-2001) was an American philosopher who taught at Princeton University and the University of California, Los Angeles and contributed to metaphysics, philosophy of mind, philosophy of language, philosophy of mathematics, philosophy of science, decision theory, epistemology, meta-ethics, and aesthetics. Lewis's papers include over four decades of his correspondence with other philosophers and scholars, including David M. Armstrong, J. J. C. Smart, Frank Jackson, D. H. Mellor, M. J. Cresswell, Allen Hazen, John Bigelow, and others, as well as drafts of his articles, books, reviews, and unpublished writings with related correspondence, his undergraduate and graduate student papers and class notes, research materials from his time at the Hudson Institute, photographs of Lewis with friends and fellow philosophers, a group of files kept by the Australian philosopher David M. Armstrong regarding Lewis, papers of Stephanie R. Lewis, and family papers.

This collection contains the musical manuscripts, musical sketches, correspondence, teaching materials, business files, and other personal papers of American composer Frank Lewin (1925-2008), who resided in Princeton from 1951 until his death. Audio and video recordings on optical media and a hard drive include music, films, and interviews; digital materials also include photographs, documents, production information, scores, parts, copyright forms, and contracts.