Duncan McArthur (March 17, 1885[1] – July 20, 1943[2]) was an archivist, educator, civil servant and political figure in Ontario.

He represented Simcoe Centre from 1940 to 1943 in the Legislative Assembly of Ontario as a Liberal.

[4] McArthur was elected to the Ontario assembly by acclamation in 1940 following the death of Leonard Simpson.

[3] McArthur died of a heart attack at his summer home at Grand Bend on Lake Huron at the age of 58.

[2] Duncan McArthur Hall at Queen's University, which houses the university's Faculty of Education, was named in his honour,[1] as was Duncan McArthur Public School, also in Kingston (now closed).