Leslie Miscampbell Frost PC CC QC (September 20, 1895 – May 4, 1973) was a politician in Ontario, Canada, who served as the province's 16th premier from May 4, 1949, to November 8, 1961.

[3] His father was a jeweller and mayor of Orillia; his mother was an important figure in the early days of The Salvation Army.

Frost was chosen as leader of the Ontario Progressive Conservative Party (the "Tories") following Premier George Drew's decision to enter federal politics.

[7] Combining small-town values with progressive policies, he took the Tories through three successive electoral victories winning majority governments in 1951, 1955 and 1959.

[4] The Frost government was the first to pass laws providing penalties for racial, ethnic, and gender discrimination on private property; these laws, introduced in the early 1950s as the Fair Employment Practices Act and Fair Accommodation Practices Act,[13] started a movement in Ontario politics that produced the Ontario Human Rights Code in 1962 and later legislation.

McGibbon, a judge from Lindsay and fellow fishing companion, regarding an anti-discrimination law about property, Frost told him that his attitudes towards people of color were out of date.

Near the end of his life, he undertook for the government of Ontario an exhaustive investigation of the state and potential of Algonquin Provincial Park.

His book Fighting Men covered the history of the 35th Regiment of Simcoe Foresters from Orillia, Ontario in the context of the First World War.

[19] His Forgotten Pathways of the Trent (published just after he died) challenged historians' previous conclusions about Indian trade and warfare routes in southern Ontario.

He was an avid U.S. Civil War buff and kept on the mantelpiece in his large library a piece of wood that was supposed to have come from Abraham Lincoln's original log cabin.