Portland is a community located in Eastern Ontario within the township of Rideau Lakes in the United Counties of Leeds and Grenville, Ontario, Canada, north of Kingston and situated on the Big Rideau Lake.
Portland was first settled in the early 19th century as one of the first settlements along the Rideau Waterway. The original seven houses in Portland, informally known as "The Landing", were a transfer point for passengers travelling from Brockville and continuing by barge to Perth.
With the completion of the Rideau Canal Waterway in 1832, steamboats and barges carrying raw materials such as cordwood, maple syrup, potash, cheese, tanned hides and salt beef were a common sight. Portland became a thriving village of trade with Kingston, Montreal and Ottawa.
The village of Portland took its name in 1843 from William Cavendish-Bentinck, 3rd Duke of Portland.
William Henry Cavendish Cavendish-Bentinck, 3rd Duke of Portland KG PC (14 April 1738 – 30 October 1809) was a British Whig and Tory statesman, Chancellor of the University of Oxford, Prime Minister of Great Britain, serving in 1783 and Prime Minister of the United Kingdom from 1807 to 1809. The 24 years between his two terms as Prime Minister is the longest gap between terms of office of any Prime Minister. He was known before 1762 by the courtesy title Marquess of Titchfield. He held a title of every degree of British nobility—Duke, Marquess, Earl, Viscount, and Baron. He is also a great-great-great-grandfather of Queen Elizabeth II through her maternal grandmother.
By the 1860s, the settlement had expanded considerably to require five hotels and, by the early 20th century, cottages were springing up around the lake and the tourist trade had begun. Advances in rail and road travel and increasing tourism offset a decline in the role of agriculture in the economy of Portland. Tourism then began to lead the economy of Portland, and still does to this day.