The Sir William Osler Collection, distinct from the Bibliotheca, is an extensive archival holding of Osler's correspondence (including eighteen hundred original letters), daybooks, accounts, engagement books, legal documents, book invoices, membership certificates, notebooks, lectures, addresses, newspaper clippings, photographs, books with manuscript additions, and miscellaneous loose items formerly inserted into individual books in his library. The collection also contains various family papers, including correspondence of Lady Grace Revere Osler and Edward Revere Osler.

There is business correspondence, 1792-1800, with letters from among others Alexander Mackenzie, Joseph Frobisher, Alexander Henry, Simon Fraser and Roderick Mackenzie. There are also minutes and resolutions of the Executors of McTavish in a bound volume; and a contemporary copy of the minutes of the executors of his will, 1805.

The World War I Clippings Collection consists of approximately 635 newspaper clippings and articles related to the First World War. Most of the clippings in this collection consist of daily reporting on troop movements and events that occurred during World War I, with some editorial and commentary pieces. Also included are clippings of maps, most from unidentified newspapers, and clipped recruitment ads. Specific topics include the sinking of the Lusitania, McGill participation in the war, the siege of Przemysl, Canadian troop deployments and casualties, and the Pope. The majority of the clippings come from the Montreal Gazette (approximately 140 clippings) and the Philadelphia Public Ledger (approximately 120 clippings). Around 50 clippings are from the The Evening Bulletin (Philadelphia) and a handful are from The Times (London). Also included are some articles from the D. A. W. War Tracts (numbers 5-7), Berlin, and the Journal of Commerce and Commercial Bulletin (New York). The fonds also contains a copy of the War Gazetteer, compiled by Charles McD. Puckette and Carrington Weems, issued by the New York Evening Post in 1914. The earliest article appears to be reporting on England's declaration of war on Germany, dated 5 August 1914.

The Red River Settlement was a colonization project set up in 1811 by Thomas Douglas, 5th Earl of Selkirk (1771-1820) who was granted 300,000 square kilometres (120,000 sq mi) of land the Hudson's Bay Company. Upon inheriting his father's title in 1799, Selkirk focused the majority of his time and resources on establishing a Scottish colony in North America. Selkirk was influenced by humanitarian luminaries such as William Wilberforce and, following the forced displacement of Scottish farmers that took place during the Highland Clearances, decided that emigration was the only viable option to improve the livelihood of the Scottish people. In July 1811 Miles MacDonell sailed from Yarmouth, England to the Hudson's Bay post at York Factory with 36 primarily Irish and Scottish settlers. Due to persuasive efforts of the North West Company only 18 settlers actually arrived at Red River in August 1812. Dogged by poor harvests and a growing population, MacDonell, now governor of Red River, issued the Pemmican Proclamation in January 1814 to prevent the export of pemmican from the colony. In doing so, MacDonell undermined the security of Red River and plunged the colony into a conflict with the North West Company that would not end until 1821.

On 11 June 1815, representatives of the North West Company attacked and fired upon the colonists, and demanded the surrender of Governor MacDonell, who, to avoid the loss of blood, gave himself up voluntarily. He was taken to Montreal as a prisoner, and charges were laid against him by his enemies, but his case was not tried. These depositions concern this case.

Items include:
Deposition of John Pritchard before A.N. McLeod, 4 June 1816, concerning the attack by Alexander MacDonell of the Hudson’s Bay Company on the tool house of the North West Company at Pimbina River, and the theft of property. Copy dated 30 December 1819.

Letter from John Pritchard to A. Norman McLeod, 28 June 1816, from the “Entrance of the Red River”, describing events at the Red River including a raid by a group led by a Canadian named Bushé, and the capture of Pritchard and his men by them.

Letter from John Johnston at Fort William, 9 Sept 1816, to A. Norman McLeod, describing his duties as acting manager there for the North West Company and the terms of the negotiations between himself and Lord Selkirk. He states that he intends to travel to Montreal.

Affidavit by the Earl of Selkirk, Montreal, 18 March 1818, concerning the dispute between himself and the North West Company, and the inability to attend the upcoming Quarter Sessions at Sandwich.

Typed transcriptions of Charles McKenzie’s narratives about the Indigenous people of MIssouri, draft and revised draft before publication; Alexander Henry’s account entitled: “Account of a visit to the Mandan and Hidatsa Indians in 1806”; and John Macdonell’s “The Red River”. Also includes drafts for work entitled, "Early fur trade on the Northern Plains : Canadian traders among the Mandan and Hidatsa Indians, 1738-1818 : the narratives of John Macdonell, David Thompson, Franc̦ois-Antoine Larocque, and Charles McKenzie" / edited and with an introduction by W. Raymond Wood and Thomas D. Thiessen. Norman : University of Oklahoma Press, 1985.

This collection, assembled by the Faculty of Dentistry, consists of curricula vitae, photocopied notices of papers Francis presented at conferences, and photocopies of his thesis and some of his published articles.

This collection is composed of McGill memorabilia collected by Ian C. Pilarczyk between 2000 and 2018, and includes articles, news clippings, programs (mostly football), pamphlets, photographs, objects (such as pins, buttons, medals, ribbons, humidors, spoons), addresses, medical notebooks, LPs and prints.

Collection consists of Canadiana assembled by Charles Kadwell: Canadiana: or, A medley of sundry matters in print and manuscript, relating principally to the Canadas; (during the period of the rebel-lions;) the other British North American colonies; and the neighbouring United States; with views, maps, plans, portraits, &c. and private journals. 2 vol. Folio. Vol 1 includes "Remarks during a voyage from London to Montreal in the year 1832"; "Notes during a trip from Montreal to Upper Canada... 3rd-18th August 1838"; "Calendar of remarkable events relating to British North America and the United States". Mostly cuttings from newspapers. A pedigree of the Kadwell family has been inserted by L.G. Macdonald, Q.C., and annotated by Robert Howard. Vol. 2, mostly newspapers.

The collection consists of falls into two series: Papers and Diaries. The Papers primarily reflect Brown's political concerns and activities in Montreal between 1832 and 1838. They include excerpts from the Vindicator newspaper, notes, resolutions, memoranda and speeches, as well as letters to Brown concerning Florida politics and the United States' negotiations with Native peoples, 1841-1843. There are also business documents and letters; essays by Brown on the 1837-1838 Lower Canada Rebellion and the annexation of Canada; and a journal kept during an ocean voyage in 1838.

The Diaries consist of seven notebooks written in pencil, or perhaps more properly dictated, by Brown in 1887-1888. They were transcribed by F. J. Nobbs in 1987.