It should not be confused with the Privy Council Office (PCO) – a department of the Government of Canada and part of the Public Service, which is expressly non-partisan.

Katie Telford manages the PMO, serving as chief of staff to Prime Minister Justin Trudeau since November 4, 2015.

Chrétien greatly depended upon the PMO, especially his chief of staff, Jean Pelletier, who ran the office from 1993 to 2001; Percy Downe, who served as his director of appointments from 1998 to 2001 and chief of staff from 2001 to 2003; and his senior advisor, Eddie Goldenberg, who had spent his entire career working with Chrétien in various ministries.

Chrétien's successor, Paul Martin, changed the structure of the PMO to more match that of the Executive Office of the President of the United States.

This model was largely retained by Martin's successor, Stephen Harper, despite the recommendations of John Gomery following his investigation into the sponsorship scandal, in which he concluded the power of the PMO should be reduced,[3] stating, "the most troubling facts were that this aberration originated in the prime minister's office in the first place and was allowed to continue for so long, despite internal audit reports, investigations, warnings, and complaints by public servants involved in the actual contracts in question.