thumb|MacKay's monument at [[Mount Pleasant Cemetery, Toronto|Mount Pleasant Cemetery in Toronto]]
Lieutenant-Colonel John Keiller MacKay (July 11, 1888 – June 12, 1970) was a Canadian soldier, lawyer and jurist. MacKay served as the 19th lieutenant governor of Ontario from 1957 to 1963.
Early life and education
John Keiller MacKay was born on July 11, 1888, in the village of Plainfield in Pictou County, Nova Scotia, the son of John Duncan and Bessie (Murray) MacKay. He was educated at the Pictou Academy, the Royal Military College (1909), Saint Francis Xavier University (BA 1912) and Dalhousie University (LL.B. 1922). A local labour organization, the Workers' Education Association (WEA), had purchased a property on O'Connor Drive, east of Broadview Avenue in Toronto, for the purpose of building a model "workingman's home",
MacKay was appointed to the Court of Appeal for Ontario in 1950 and remained on the court until 1957, when he was named the lieutenant governor of Ontario. He served as lieutenant governor until 1963, and he opened the lieutenant governor's New Year's Levee to the general public for the first time.
In 1964, he was a founder of the Canadian Civil Liberties Association, serving as honorary president.
In 1967, he was made an Officer of the Order of Canada. He was also a Knight of Grace of the Venerable Order of St. John and was responsible for bringing the Order of Saint Lazarus to Canada in 1962.
Personal life
He was married to Katherine "Kay" Jean MacLeod and had three sons. He died in Toronto on June 12, 1970,