John Timothy Irvine Porteous, CM (August 31, 1933 – February 11, 2020) was a Canadian administrator.

A native of Montreal, he studied at Bishop's College School, Selwyn House School^[1] and McGill University, where he earned both a bachelor of arts and a bachelor of civil law.^[2] Porteous first met Pierre Trudeau in 1957 when the two were students traveling in West Africa for a World University Service of Canada seminar, for which Porteous represented McGill, where he had previously been responsible for the outstanding 1957 student production of My Fur Lady, which he co-wrote.

He and Trudeau remained friends and became even closer when Porteous took a two-year leave of absence from his law practice in 1966 and went to Ottawa to work as an executive assistant to Treasury Board president Charles Drury, before volunteering as a speechwriter on Trudeau's 1968 leadership campaign.

He is credited with introducing Trudeau to Margaret Sinclair, who Trudeau later married.^[3]

When Trudeau won the Liberal Party leadership campaign, on becoming Prime Minister later in 1968 he offered Porteous a job as his executive assistant, a position he held for five years.^[4] After his time in government, Porteous went on to head both the Canada Council and the Ontario College of Art and Design.

Porteous was perhaps best known for his 12-year tenure as associate director and director of the Canada Council.^[5] He was appointed to be a Member of the Order of Canada in October 2003, in recognition of his public service.

• Porteous, Barry. The Porteous Story, (Kingston, Ontario, published privately 1975)