James Chalmers McRuer OC (August 23, 1890 – October 6, 1985) was a Canadian lawyer, judge, commissioner and author in Ontario.

During World War I, he served in the Canadian Field Artillery as a lieutenant.

After the war, from 1921 to 1925 he was an Assistant Crown Attorney for Toronto and County of York.

He ran unsuccessfully as the Liberal candidate in High Park in the 1935 federal election losing to Alexander James Anderson.

In 1968, he was made an Officer of the Order of Canada "for his services in the profession of law and as a member of many Royal Commissions".