Erastus Wiman (21 April 1834 – 9 February 1904) was a Canadian journalist and businessman who later moved to the United States.
Wiman was born in Churchville, Upper Canada, now part of Ontario, on April 21, 1834.
He worked as a reporter for the Toronto Globe and moved into business for R.G. Dun and Co. He was later transferred to New York and would become general manager of the company. He became president of the Great Northwestern Telegraph Company of Canada.
He was a proponent of reciprocity, now known as free trade, between Canada and the United States.