The Department of the Provincial Secretary evolved from the office of Colonial Secretary and Registrar. The office of Colonial Secretary was essentially an assistant to the Lieutenant-Governor whose duties including the safe keeping of the Colony's records, the recording of all grants, patents, records and commissions as well as preparing commissions and instruments under the Great Seal for the signature of the Lieutenant-Governor. The Colonial Secretary was a member of the Executive Council.

J.E. Carmichael was appointed Colonial Secretary and Registrar on 10 February 1820 and also acted as Receiver of Quit Rents. He had been appointed Clerk of His Majesty's Council on 25 September 1819. As clerk of HM Council, duties included the taking down and safe keeping of the Executive Council minutes and preparing all warrants for the issue of monies from the Treasury of the colony.

An act relating to certain departments of the public service, passed 29 April 1876 (39 Vic., Cap. 10) combined the offices of Colonial Secretary and Colonial Treasurer, and renamed the office Provincial Secretary and Treasurer, an appointment to be held by a member of government. George Wastie DeBlois, was appointed first Provincial Secretary-Treasurer. This act also established the offices of Assistant Provincial Secretary, who also served as Clerk of the Executive Council and Assistant Provincial Treasurer. The act respecting certain departments of the Public Service passed 7 June 1879 (42 Vic., Cap. 5) combined the offices of Provincial Secretary and Treasurer and Commissioner of Crown and Public Lands in one person. The office of Clerk of Executive Council was transferred from the Assistant Provincial Secretary's duties and combined with Provincial Auditor to form one position.

In 1897, the Department of Agriculture was established in P.E.I. An act to amend the acts respecting certain departments of the public service, assented to 1 May 1897 (60 Vic., Cap. 1) combined the positions of Provincial Secretary-Treasurer and Commissioner of Agriculture. The offices of Registrar of Deeds and Commissioner of Public Lands, were also combined. An act respecting certain departments of the Public Service assented to 30 April 1904 (4 Edward VII, Cap. 8) returned the duties of Clerk of the Executive Council to the Assistant Provincial Secretary-Treasurer.

Section 7-1 of The Statute Law Amendment Act (14 Geo., Cap. 12) in 1924 changed the name of Commissioner of Agriculture to Minister of Agriculture and section 9 of the same act indicated that one person might hold any one or more of the following offices: Premier, President of the Executive Council, Attorney General, Minister of Public Works, Minister of Agriculture, Provincial Treasurer or Provincial Secretary, a scenario which was often followed.

An act to amend an act respecting certain departments of the public service (18 Geo. V., Cap. 17) in 1928 changed the name of Assistant Provincial Secretary-Treasurer to Deputy Provincial Secretary-Treasurer. This office also included the duties of Clerk of the Executive Council, a position appointed by, and held during the pleasure of the Lieutenant-Governor in Council.

The Public Departments Act (3 Geo., Cap. 42) in 1939 provided for a separate Treasury Department, presided over by a Minister of the Crown know as the Provincial Treasurer, and for a Minister of the Crown known as the Provincial Secretary. Yet one person still held the office of Deputy Provincial Secretary-Treasurer and Clerk of the Executive Council whose duties included the registering of all proclamations and orders-in-council of the Privy Council of Canada signifying the Royal allowance or disallowance of any act passed by the Legislature. This act also gave the Department of Agriculture a separate department and minister.

It wasn't until 1954 (3 Elizabeth II., Cap. 29) in the Act to Amend the Public Departments Act that the Department of the Provincial Secretary was established, presided over by a Minister of the Crown called the Provincial Secretary who was also custodian of the Great Seal of the Province.

In the 1950's, the department was the smallest in government with a minister, deputy minister, and one or two support staff, responsible for the administration of the following acts: The Companies Act, the Marriage Act, Highway Traffic Act, Trade Union Act, Cooperative Associations Act, Credit Union Act, and the Securities Frauds Prevention Act. The Deputy Provincial Secretary, at this time also acted as Clerk of the Executive Council responsible for the care of Cabinet minutes and matters of protocol, as well as acting as Succession Duty Officer, Superintendent of Insurance and Deputy Administrator of several acts. Some of the branches of the Department of the Provincial Secretary were Motor Vehicle, Duplicating, Legislative Library, Tourist and Information, and Audit Office.

By the 1960's the Department of the Provincial Secretary was responsible for some 41 acts including legislation pertaining to licensing, companies, emergency measures, elections, the Queen's Printer, Public Archives, marriages, highway traffic, Public Utilities Commission, real estate, cemeteries, civil servants, Fishermen's Union and floral emblem and coat of arms. The department raised revenue for the province through licensing and registration fees, taxation, printing fees, sale of copies of statutes and bills, consumer services and a federal contribution towards civil defence.

By the late 1970's, the Department of the Provincial Secretary included the following divisions: Corporations, Consumer Services, Highway Safety, Public Archives, Queen's Printer, and Superintendent of Insurance and until 1975, the Emergency Measures Organization, which operated under the authority of the Emergency Measures and Disaster Act, 1959.

Some individuals who served as Colonial or Provincial Secretary include: Thomas DesBrisay, J.E. Carmichael, John P. Collins, T.H. Haviland, James Warburton, Francis Longworth, George Coles, Henry Haszard, William H. Pope, Thomas Heath Haviland, Benjamin Davies, G.W. DeBlois, Albert Hensley, Thomas W. Dodd, Neil McLeod, Donald Ferguson, Angus McMillan, Frederick Peters, J. Walter Jones, J. Wilfred Arsenault, B.Earle MacDonald, J. David Stewart, T. Earle Hickey, G.D. Dennis, Dr. L. George Dewar, W. Bennett Campbell, Arthur J. MacDonald, George A. Proud. The office of Assistant or Deputy Provincial Secretary Treasurer and Clerk of the Executive Council has been filled by: Wm. S. Keating, George Thresher, Malcolm McNeill, John Ball, R. Hyndman, Andrew Mitchell, John William Morrison, Peter Stewart DesBrisay, William C. DesBrisay, Arthur Newbury, W.H. Crosskill, Earle K. Kennedy, J.W. MacKinnon, P.S. Fielding, Wendall MacKay, G. Lorne Monkley.

Leo F. Rossiter and Arthur J. Currie served respectively as Minister and Deputy Minister of the Department of the Provincial Secretary when it ceased to exist after 1979.